Lume 101: Watch Luminescence Explained

Lume 101: Watch Luminescence Explained

Ultimate Guide: AP Environmental Science Notes

Ecosystem : A community of living (biotic) organisms interacting with the non-living (abiotic) components of their environment as a system through various nutrients and energy cycles.

Population : Organisms of the same species that interact with each other and occupy a specific area.

Species : Organisms that resemble each other; are similar in genetic makeup, chemistry, and behavior; and are able to interbreed and produce fertile offspring.

Organism : A living thing that can function on its own.

Types and amounts of resources available.

Niche : It reflects the specific adaptations that a species has acquired through evolution.

Physical environment : It influences how organisms affect and is affected by resources and competitors.

Ecological Niche : A particular area within a habitat occupied by an organism, as well as the function of that organism within its ecological community.

Symbiosis : A term used to describe any type of close and long-term biological interaction between two different biological organisms of the same or different species.

Saprottrophism : Saprotrophs obtain their nutrients from dead or decaying plants or animals through the absorption of soluble organic compounds.

Specialist predators only prey upon certain organisms.

Opportunistic predators kill and eat almost anything.

Parasitism : The interaction between two species whereby one species is benefited, and the other species is harmed.

Mutualism : The interaction between two species whereby both species benefit.

Competition is prominent in predator&#;prey relationships , with the predator seeking food and the prey seeking survival.

Interspecific : competition between members of different species.

Intraspecific : Competition between members of the same species.

It is the driving force of evolution whether it is for food, mating partners, or territory.

Competition : It can be either intraspecific and interspecific.

using something that another organism created.

using another organism for housing, and

using another organism for transportation

Commensalism : The interaction between two species whereby one organism benefits and the other species is not affected.

Example: The black walnut tree releases a chemical that kills neighboring plants.

Amensalism : The interaction between two species whereby one species suffers and the other species is not affected.

Some factors can control an organism's abundance or distribution if they exceed its tolerance limits.

Law of Tolerance : It states that the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors.

the amount of dissolved oxygen, light, or

the pH of the water,

the available amount of water and light, and

Limiting Factor : Any abiotic factor that limits or prevents the growth of a population.

If the prey species rapidly multiply, the number of predators increases until the predators eventually eat so many of the prey that the prey population dwindles again.

Predator-prey cycles are based on a feeding relationship between two species:

Temporal partitioning : It occurs when two species eliminate direct competition by utilizing the same resource at different times

Spatial partitioning : It occurs when competing species use the same resource by occupying different areas or habitats within the range of occurrence of the resource

Morphological partitioning : It occurs when two species share the same resource but have evolved slightly different structures to utilize the same resource

The geographical distribution of the various terrestrial biomes is controlled primarily by the average air temperature and the amount of rainfall the biome receives.

Temperature and precipitation are the most important determinants of biomes.

Biomes : These are major regional or global biotic communities characterized by dominant forms of plant life and the prevailing climates

They spend time in underground burrows where it is cold.

They are often nocturnal.

They perform their entire life cycle from seed to flower to seed within a single growing season; and

They are dependent on water for germination;

They also secrete toxins into the soil to prevent interspecific completion.

They have sharp spines that create shade, reduce drying airflow, discourage herbivores, and reflect sunlight.

vertical orientation to minimize exposure to the sun; and

shallow roots to collect and store water after short rainfalls;

Plants that have fleshy leaves or stems that store water.

Arctic tundra is a cold desert due to the low amount of rainfall it receives yearly.

Most deserts are located between 15° and 35° north and south latitudes.

Daily extremes in temperature result from exceptionally low humidity as water vapor tends to block solar radiation.

They cover about 20% of Earth&#;s surface and occur where rainfall is less than 20 inches (50 cm) per year.

Deserts : Defined in terms of the amount of rainfall they receive, not temperature.

Open canopy : Tree crowns cover less than 20% of the ground surface.

The majority (80%) of the forest biome.

Closed canopy : Tree crowns cover more than 20% of the ground&#;s surface.

Ecozones like boreal forests near the poles and tropical forests near the equator are formed by forests at different latitudes and elevations.

Forests cover about one-third of Earth's land surface, mostly in North America, the Russian Federation, and South America, and account for 75% of gross primary productivity and plant biomass.

Tree canopy is multilayered and continuous, allowing little light penetration.

Temperature is warm to hot and varies little throughout the year.

Most nutrients are rapidly assimilated and stored in plant tissue, leaving soil nutrient-poor.

The length of daylight is 12 hours and varies a little year-round

Distinct seasonality where winter is absent and only two seasons are present.

Decomposition is rapid and soils are subject to heavy leaching.

Development, land clearing, and timbering have left few temperate forests.

The tree canopy allows light to penetrate, resulting in well-developed and diverse understory vegetation and animal stratification.

Temperature varies from &#;20°F to 85°F (&#;30°C to 30°C).

Have a distinct winter, moderate climate, and a 140&#;200-day growing season during four to six frost-free months.

Occur in eastern North America, northeastern Asia, and western and central Europe.

Some animals migrate to warmer climates during the winter months.

Birds have feathers and many animals have thick fur to protect them from cold weather.

In winter, when food is scarce, many animals hibernate to conserve energy and build fat in summer.

As temperatures rise, trees can start photosynthesis with their year-round needles.

The understory has many herbaceous and shrub species.

Grassy understories in pine forests often burn in ecologically important wildfires.

Understory : Layer made up of young trees, short species of trees, shrubs, and soft-stemmed plants.

These forests have two layers:

These forests have cedar, cypress, fir, juniper, pine, redwood, and spruce.

Common in coastal areas with mild winters and heavy rainfall, or inland in drier climates or mountains.

Found in temperate regions with warm summers, cool winters, and enough rainfall to support forests.

Cold temperatures, wet soil during the growing season, and needle and moss acids slow organic matter decay.

The harsh climate in the taiga limits both productivity and resilience.

Northern Taiga: It is more barren as it approaches the tree line and the tundra biome.

Southern Taiga : Also known as boreal forest, consists primarily of cold-tolerant evergreen conifers with needle-like leaves, such as pines, spruces, and larches.

Taiga : Largest terrestrial biome; found in northern Eurasia, North America, Scandinavia, and two-thirds of Siberia.

There are two main divisions of grasslands:

Grasslands are characterized as lands dominated by grasses rather than by large shrubs or trees.

Seasonal fires help savannas' biodiversity during dry and rainy seasons.

Deciduous trees and shrubs are scattered across the open landscape.

Savanna soil drains quickly and has a thin layer of humus to nourish vegetation.

Savannas are found in warm or hot climates with an annual rainfall of 20 to 50 inches (50&#;130 cm) concentrated in six to eight months, followed by a long drought when fires can occur.

Savannas : These are grasslands with scattered individual trees and cover almost half the surface of Africa and large areas of Australia, South America, and India.

In river valleys, cottonwoods, oaks, and willows grow, along with some flowers.

Seasonal drought, fires, and large mammal grazing prevent woody shrubs and trees from establishing.

Deep, multi-branched grass roots grow and decay in the dark, fertile soil, enriching it.

Drought and fires affect biodiversity in the savanna.

Climate is characterized by hot summers and cold winters, and rainfall is moderate.

the plains and prairies of central North America.

the steppes of Russia, and

Temperate Grasslands : Here grasses are the dominant vegetation, while trees and large shrubs are absent.

Dead organic material functions as a nutrient pool in the tundra.

Due to the Arctic tundra 's unique conditions, the biota is highly specialized and sensitive to environmental change.

Tundra : It has extremely low temperatures, large repetitive population changes, limited soil nutrients, little precipitation, low biotic diversity, poor drainage, short growing and reproductive seasons, and simple vegetation structure.

Reptiles and amphibians are few or absent.

Migratory birds include ravens, falcons, terns, snowbirds, and various species of gull. Insects include mosquitoes, flies, moths, grasshoppers, and bees.

Due to the scarcity of food in the winter, a lot of animals hibernate or move south.

Mammals and birds also have additional insulation from fat.

Animals are highly specialized for long, cold winters and quick breeding and raising young in summer.

Food webs are simple and characterized by low biodiversity.

Most plants reproduce by budding and division, not by flowering.

They can photosynthesize in low light and temperatures.

All plants are adapted to sweeping winds and disturbances of the soil.

Bogs and ponds form when water saturates the upper surface, providing moisture for cold-resistant plants like low shrubs, mosses, grasses, approximately 400 flower varieties, and lichen.

Yearly precipitation, including melting snow, is 6 to 10 inches (15 to 25 cm).

This biome survives because summer temperatures range from 37°F to 54°F (3°C to 12°C) and winter temperatures average &#;30°F (&#;34°C).

The very short growing season averages around 50 days per year.

Arctic tundra : It circles the North Pole and extends south to the taiga, is cold, dry, and desert-like.

Animals living in the alpine tundra include mountain goats, sheep, elk, birds, beetles, grasshoppers, and butterflies.

Plants are very similar to those of the Arctic tundra and include grasses, dwarf trees, and small-leafed shrubs.

The soil in the alpine tundra is well-drained.

The growing season is approximately 180 days, with nighttime temperatures usually falling below freezing.

Alpine tundra: It is located on mountains throughout the world at high altitudes where trees cannot grow.

Water buoyancy reduces the need for legs and trunks.

Water's thermal capacity is high, most aquatic organisms don't need to regulate temperature.

Water allows for the effective dispersal of gametes and larvae to new areas.

Krill: These are key food sources in this ecosystem and serve as food for many predators.

The ice sheet is formed from compressed snow that rarely melts.

Rainfall is rare and usually occurs in coastal and island areas during summer.

Antarctica's total precipitation (mostly snow) averages ~6.5 inches (166 mm) per year, with deserts in the interior receiving less than 10 inches (~250 mm).

The interior averages &#;70°F (&#;57°C), while the coast averages 14°F (&#;10°C).

Antarctica has the coldest climate on Earth.

Oceans have the highest net primary productivity per unit area of Earth.

Marine algae and photosynthetic bacteria absorb carbon dioxide and produce oxygen in the oceans.

Evaporation of seawater is the primary source of most of the world&#;s rainfall.

Oceans cover approximately 75% of Earth&#;s surface and have a salt concentration of about 3%.

Cold bottom water flows south to Antarctica and warms and rises to the surface in the Pacific and Indian Oceans.

This water sinks because it loses heat and becomes cooler and denser.

The Gulf Stream heats northern latitudes by entering the Norwegian Sea.

Thermohaline currents drive a conveyor belt of ocean water that moves constantly, unlike most surface currents, which are driven by winds.

In the Northern Hemisphere, north-flowing ocean currents from the equator are warmer than south-flowing ones.

Deeper ocean waters are colder and denser than near-surface waters.

Wind patterns caused by tropical air flowing to the polar regions drive surface ocean currents.

Convection: The circular motion that occurs when warmer air or liquid rises, while the cooler air or liquid sinks.

Air and oceanic currents carry heat from the equator to the poles.

Summer and winter air temperature differences are greater in the Northern Hemisphere.

Land dominates the Northern Hemisphere and oceans the Southern.

The layer just above the depth where the rate of carbon dioxide uptake by plants is equal to the rate of carbon dioxide production by animals.

Photic Zone : The uppermost layer of water in a lake or ocean that is exposed to sunlight down to the depth where 1% of surface sunlight is available.

Neretic Zone : Also known as the sublittoral zone, this zone extends to the edge of the continental shelf.

Littoral Zone : Also known as the intertidal zone, it is the part of the ocean that is closest to the shore.

Most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates, commonly known as zooxanthellae , that live within their tissues.

Polyps : Small, sac-like animals with a set of tentacles surrounding a central mouth opening and an exoskeleton made of calcium carbonate at the base.

Corals : These are marine invertebrates that typically live in compact colonies of many identical individual polyps.

They usually form when islands, often the tops of underwater volcanoes, surrounded by fringing reefs, sink into the sea, or the sea level rises around them.

These are rings of coral that create protected lagoons and are usually located in the middle of the sea.

At their shallowest point, they can reach the water&#;s surface, forming a &#;barrier&#; to navigation.

These are also parallel to the coastline but are separated by deeper, wider lagoons.

They are the most common type of reef.

They grow near the coastline around islands and continents and are separated from the shore by narrow, shallow lagoons.

organic materials, such as decaying plant or animal matter.

inorganic materials, such as silt or sand, and/or

The material at the bottom of a lake can be composed of a wide variety of

The depth to which light can reach in lakes depends on turbidity or the amount and type of suspended particles in the water.

Artificial lakes : These are constructed for hydroelectric power generation, recreational purposes, industrial and agricultural use, and/or domestic water supply.

Runoff is carried by streams and channels from the lake&#;s catchment area, groundwater channels, and aquifers.

Manmade sources from outside the catchment area

Tectonic uplift of a mountain range that creates a depression that accumulates water.

Salt or saline lakes that form where there is no natural outlet or where the water evaporates rapidly.

Advance and retreat of glaciers that scrape depressions in Earth&#;s surface where water can accumulate.

Processes that form lakes include the following:

Most lakes on Earth are located in the Northern Hemisphere at higher latitudes.

Lakes: These are large natural bodies of standing freshwater formed when precipitation, runoff, or groundwater seepage fills depressions in Earth&#;s surface.

Profundal Zone : It is deep, no-light regions, too dark for photosynthesis; low oxygen levels; inhabited by fish adapted to cool, dark waters

Littoral Zone : It is shallow, close to shore, extends to depth penetrated by light; rooted and floating plants flourish

Limnetic Zone : A well-lit, open surface water, farther from shore, extends to a depth penetrated by light, occupied by phytoplankton, zooplankton, and higher animals; produces food and oxygen that supports most of a lake&#;s consumers

Benthic Zone : The bottom of lake, organisms can tolerate cool temperatures and low oxygen levels.

Pollution from fertilizers often causes algae populations to dramatically increase causing a decrease in the oxygen content of the water, with detrimental consequences for life in the lake.

Eutrophication occurs over long periods of time as runoff brings in nutrients and silt.

High organic matter content in benthos, which leads to high decomposition rates and potentially low oxygen.

Mesotrophic (Middle-Aged Lake) : Moderate nutrient content and moderate amounts of phytoplankton; reasonably productive.

Oligotrophic (Young Lake) : Deep, cold, small surface area relative to depth; nutrient-poor, phytoplankton are sparse; not very productive; doesn&#;t contain much life; waters often very clear; and sediments are low in decomposable organic matter.

The surface and water near the shore are warmed by the sun, making them less dense, so that they form a surface layer called the epilimnion.

Deep water is insulated from the sun and stays cool and denser, forming a lower layer called the hypolimnion .

The density of water increases as temperature decreases until it reaches its maximum density at about 39°F (4°C), causing thermal stratification&#;the tendency of deep lakes to form distinct layers in the summer months.

The stratification or layering of water in lakes is the result of density changes caused by shifts in temperature.

When this occurs, winds blowing over the lake again set up a full circulation system.

With spring, the surface ice begins to melt, and cold surface waters warm until they reach the temperature of the bottom waters, again producing a fairly uniform temperature distribution throughout the lake.

Colder water remains above, potentially becoming capped by an ice layer, which further prevents the winds from stirring the water mass.

Thus, as lake waters move toward freezing and reach 4°C, the water sinks to the lake bottom.

As the winter approaches in areas where subfreezing temperatures are common, the lake surface temperatures approach the freezing mark.

During this time, strong fall winds move the surface water around, which promotes mixing with deeper water.

With the arrival of fall and cooler air temperatures, water at the surface of a lake begins to cool and becomes heavier.

As summer progresses, temperature differences increase between the layers, and a thin middle layer, or thermocline, develops, where a rapid transition in temperature occurs.

During the summer, the sun heats water near the surface of lakes, which results in a well-defined warm layer of water occurring over a cooler one.

Seasonal turnover : Refers to the exchange of surface and bottom water in a lake or pond that happens twice a year.

The water found in wetlands can be saltwater, freshwater, or brackish

Wetlands : These are areas that are covered with water at some point in the year and that support aquatic plants.

Serving as nurseries for fishes and shellfishes.

As sediment flows through a wetland from the surrounding watershed, it becomes trapped, reducing the siltation into lakes, rivers, and streams.

Dumping fill material buries hydric soil, which is permanently or seasonally saturated by water, resulting in anaerobic conditions, and lowers the water table so that water-loving plants cannot compete with upland plants.

Lack of sediment renewal also affects fish nurseries and bird breeding grounds.

Roads and railroads narrow the floodplain, increase flooding, and create low-quality wetlands upslope of the roads by interrupting surface water and groundwater flows, which reduces sediment renewal and depletes nutrients for native vegetation and higher trophic levels.

It affects breeding grounds for fish and other wildlife and also produces noise pollution, which affects wildlife behavior.

It can result in the loss of wetland vegetation.

It causes pollution and erosion as part of the drilling process.

Oil exploration and spills cause a disruption in wildlife both on land and in the sea.

It eliminates the water source of wetlands through land fractures.

Mine wastes are often deposited in the floodplain.

Logging decreases biodiversity in wetlands as natural habitats are destroyed.

ability to live off of a wide range of food types,

Native species cannot always compete with introduced species.

Wetland vegetation removes water through evapotranspiration, alters water and soil chemistry, provides wildlife habitats, and reduces erosion.

Freshwater is depleted from wetlands for residential and commercial purposes.

Water is diverted around wetlands, lowering the water table and increasing anthropogenic pollution.

Dam sediments prevent them from replenishing barrier islands and beach sediments.

Dams and levees block nutrient-rich sediments from entering the floodplain, harming wetlands' food webs.

It may hurt marine life, habitats, and human communities that depend on ocean for survival.

The depletion of native species of fish and shellfish affects the wetland food webs.

This lowers the water table and dries out the wetland.

Wetlands have been drained to utilize the rich organic soil.

the release of stored water in ice and snowpack.

Rivers and streams move continuously in a single downhill direction, and their inputs include

The nutrient content of rivers and streams is largely determined by the terrain and vegetation of the area through which they flow and is also determined by adjacent and overhanging vegetation, the weathering of rocks in the area, and soil erosion.

Tributaries join to form rivers, which empty into oceans at estuaries.

As a result of large amounts of sediment and nutrients, the water is murky and warmer.

Species diversity is usually greater than in the source zone.

The water is less clear as it contains more sediment and nutrients, with the substrate beginning to accumulate silt.

Contains slower, warmer, wider, and lower-elevation moving streams, which eventually join to form tributaries.

The water has relatively high oxygen levels and may include freshwater species such as trout.

Contains headwaters or headwater streams and often begins as springs or snowmelt of cold, clear water with little sediment and relatively few nutrients.

Riparian areas : These are lands adjacent to creeks, lakes, rivers, and streams that support vegetation dependent upon free water in the soil.

The calcium comes from the weathering of calcium-silicate rocks, which causes the silicon in the rocks to combine with oxygen to form sand or quartz, leaving calcium ions available to form limestone.

Sedimentary Deposits : Limestone (CaCO3) is the largest reservoir of carbon in the carbon cycle.

Marine organisms also require carbon for the production of shells, skeletons, and coral.

Oceans : The carbon in carbon dioxide dissolved in seawater is utilized by phytoplankton and kelp for photosynthesis.

Terrestrial Biosphere : Forests store about 90% of the planet&#;s above-ground carbon and about 75% of the planet&#;s soil carbon.

Plant Matter : A portion of atmospheric carbon (~15%) is removed through photosynthesis.

The major reservoirs or &#;sinks&#; of carbon include the following:

Due to rising CO2 concentrations, oceanic acidity may slow the natural precipitation of calcium carbonate, reducing the ocean's capacity to absorb CO2.

The creation of coral reefs and the viability of externally fertilized egg cells are disrupted by ocean acidification caused by carbon dioxide absorption.

One-third of soil carbon is stored in organic form.

Carbon enters the ocean mostly by dissolving atmospheric carbon dioxide.

Carbon can precipitate into the ocean's deeper, more carbon-rich layers as dead soft tissue or calcium carbonate in shells.

It is also found in carbon dioxide, which makes up less than 1% of the atmosphere.

Carbon: It is exchanged among the biosphere, geosphere, hydrosphere, and atmosphere and is the basic building block of life and the fundamental element found in carbohydrates, fats, proteins, and nucleic acids.

After the Industrial Revolution, the deforestation of old-growth forests and the combustion of fossil fuels released carbon stored in long-term carbon sinks, causing climate change and the following environmental impacts:

Before the Industrial Revolution, CO2 transfer rates through photosynthesis, cellular respiration, and fossil fuel burning were balanced.

Denitrification : Anaerobic bacteria convert ammonia into nitrites (NO2&#;), nitrates (NO3&#;), nitrogen gas (N2), and nitrous oxide (N2O) to continue the cycle.

Ammonification : Decomposing bacteria convert dead organisms and wastes, which include nitrates, uric acid, proteins, and nucleic acids, to ammonia (NH3) and ammonium ions (NH4+)&#;biologically useful forms.

Assimilation : Plants absorb ammonia (NH3), ammonium ions (NH4+), and nitrate ions (NO3&#;) through their roots.

Nitrification : Ammonia (NH3) is converted to nitrite (NO2&#;) and nitrate (NO3&#;), which are the most useful forms of nitrogen to plants.

The key participants in nitrogen fixation are legumes, such as alfalfa, clover, and soybeans, and nitrogen-fixing bacteria known as Rhizobium .

Nitrogen Fixation : Atmospheric nitrogen is converted into ammonia (NH3) or nitrate ions (NO3&#;), which are biologically usable forms of nitrogen.

The natural cycling of nitrogen , in which atmospheric nitrogen is converted to nitrogen oxides by lightning and deposited in the soil by rain, where it is assimilated by plants and either eaten by animals or decomposed back to elemental nitrogen by bacteria, includes the following processes:

It is a limiting nutrient in terrestrial ecosystems, so its presence often limits food production.

Nitrogen is a key component in nucleic acids (DNA and RNA) and proteins.

It is needed for photosynthesis and plant growth in chlorophyll.

Fossil fuel combustion, inorganic fertilizer use, and wastewater and sewage production have drastically altered the nitrogen cycle.

Though atmospheric nitrogen (N2) is abundant, it has limited use biologically, which leads to a scarcity of usable forms of nitrogen in terrestrial and aquatic ecosystems.

Other nitrogen stores include the organic matter in the soil and the oceans.

It is an essential element needed to make amino acids, proteins, and nucleic acids.

Nitrogen makes up 78% of the atmosphere.

Clearing tropical habitats for farming, which reduces the amount of phosphorus that is readily available because it is contained in the vegetation.

Applying phosphate-rich guano and other fertilizers containing phosphate to fields.

This growth results in decreased oxygen content in the water, which then kills other aquatic organisms in the food web.

Allowing runoff from feedlots, fertilizers, and municipal sewage plants to collect in lakes, streams, and ponds increases cyanobacteria, green algae, and aquatic plants.

Humans have impacted the phosphorus cycle in several ways, as follows:

It is often a limiting factor for soils due to its low concentration and solubility, and it is a key element in fertilizer.

It is slowly released from terrestrial rocks by weathering and the action of acid rain and then dissolves into the soil and is taken up by plants.

It is found in the form of the phosphate ion or the hydrogen phosphate ion.

Phosphorus is not found in the atmosphere; rather, the primary sink for phosphorus is in sedimentary rocks.

Phosphorus is essential for the production of nucleotides, ATP, fats in cell membranes, bones, teeth, and shells.

Runoff : Part of the water cycle that flows over land as surface water instead of being absorbed into groundwater or evaporating

Precipitation : Rain, snow, sleet, or hail that falls to the ground

Infiltration : The process by which water on the ground surface enters the soil

Evapotranspiration : The process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants

Evaporation : The process of turning from a liquid into vapor

Condensation : The conversion of a vapor or gas to a liquid

Processes involved in the water cycle include the following:

The water cycle is in a state of dynamic equilibrium by which the rate of evaporation equals the rate of precipitation.

Oceans are also the source of 86% of all global evaporation, with evaporation from the sea surface keeping Earth from overheating.

The oceans hold 97% of all water on the planet and are the source of 78% of all global precipitation.

Water cycle : It is powered by energy from the sun, which evaporates water from oceans, lakes, rivers, streams, soil, and vegetation.

Of the freshwater that is available, most of it is trapped in glaciers and ice caps, with the rest found in groundwater, lakes, soil moisture, atmospheric moisture, rivers, and streams.

Over 70% of Earth&#;s surface is covered by water, with oceans holding about 97% of all water on Earth, and freshwater making up only about 3%.

The polarity of water helps to dissolve many compounds.

Floating ice : Essential to life near the poles, results from the different ways water molecules arrange themselves at different temperatures.

Capillary action : A result of hydrogen bonding, helps tree roots take up water, allowing trees to grow as large as they do.

Water is a polar molecule, which means the following:

The temperature of water changes slowly due to its high specific heat capacity.

A lot of energy is needed to evaporate water.

The renewal of Earth&#;s freshwater supply depends on the regular movement of water from Earth&#;s surface into the atmosphere and back again.

Water table : The level below which the ground is saturated with water.

Unsaturated zone : The zone immediately below the land surface where the open spaces in the soil contain both water and air, but are not totally saturated with water.

Recharge zone : The surface area above an aquifer that supplies water to the aquifer.

As a result of impermeable material above and below the aquifer, the water is under pressure.

Confined &#;artesian well&#; aquifer : An aquifer below the land surface that is saturated with water.

Aquifer : A geologic formation that contains water in quantities sufficient to support a well or spring.

Changes in global weather patterns also reduce aquifer inputs, jeopardizing groundwater levels.

As human populations increase, the rates of groundwater extraction likewise increase.

Though agriculture is the largest sector responsible for aquifer depletion, domestic and municipal withdrawals also affect groundwater levels in many areas around the world.

When the rate of groundwater extraction is greater than the rate of aquifer recharge, the net effect is a drop in the water table.

Saltwater intrusion : The movement of saltwater into freshwater aquifers, which can lead to contamination.

Reduction of water in lakes, ponds, and streams

Water shortages : Since groundwater is the main water source for many populations, residents of these areas may experience water insecurity for domestic and agricultural needs.

Land subsidence : The sinking of land that results from groundwater extraction.

Increased costs as more energy is required for pumping

Photosynthesis : The plants remove carbon dioxide from the atmosphere and use light energy to produce carbohydrates and other organic compounds:

Plants are able to use this light energy to create food through the process of photosynthesis.

The ultimate source of energy is the sun .

the availability of water; and

the amount of light and its wavelength;

Factors that affect the rate of photosynthesis include:

Since plants produce less carbon dioxide than they absorb, they, therefore, become net sinks of carbon.

Oxygen gas is released into the atmosphere during photosynthesis, and plants emit carbon dioxide during respiration.

The energy derived from the oxidation of glucose during cellular respiration is then used to form other organic compounds such as cellulose, lipids, amino acids, and eventually proteins.

Plants capture light primarily through the green pigment chlorophyll , which is contained in organelles called chloroplasts .

Trophic Level : The position an organism occupies in a food chain and is the number of steps it is from the start of the chain.

Entropy : A natural tendency of any isolated system to degenerate from an ordered state into a more disordered state.

Second Law of Thermodynamics : States that as energy is transferred or transformed, more and more of it is wasted.

Energy pyramids will always have an upright pyramid shape if all sources of food energy are included.

Aquatic predators also tend to have a lower death rate than the smaller consumers, which further contributes to the inverted pyramid pattern.

The fish eating the zooplankton live for several years.

Zooplankton eats the phytoplankton live for several weeks.

Primary consumers have longer life spans and slower growth rates and accumulate more biomass than the producers they consume.

Only 10% of a generation's biomass is transferred.

One generation of zooplankton may consume several generations of phytoplankton.

Zooplankton has a longer lifespan than phytoplankton, so its biomass is higher.

In some instances, biomass pyramids can be inverted , and are often seen in aquatic and coral reef ecosystems.

Ecological pyramids : These show ecosystem properties by placing primary producers at the base and decreasing energy as species move away from them.

This energy is then stored in the molecule adenosine triphosphate (ATP).

In respiration, glucose is oxidized by the cells to produce carbon dioxide, water, and chemical energy.

Cellular respiration is the opposite of photosynthesis.

Secondary production : The generation of biomass by heterotrophic consumers in a system, is driven by the transfer of organic material between trophic levels, and represents the quantity of new tissue created through the use of assimilated food by organisms responsible for secondary production.

Productivity: Refers to the rate of generation of biomass in an ecosystem and is expressed in units of mass per unit surface area (or volume) per unit time, with mass referring to dry matter or to the mass of carbon generated.

10% Rule : It states that energy is lost mostly as heat from one stage to the next.

8% of solar energy is available to plants, 1% of which is used for photosynthesis. 15% is reflected back into space, and 80% is absorbed by Earth.

Sunlight is the ultimate source of energy required for most biological processes.

The remaining energy is typically lost as heat during metabolic reactions, temperature control, incomplete digestion, and waste product decay .

Only about 10% of the energy used to move from one trophic level to the next is used to turn organic matter into tissue.

the producers in ocean or aquatic ecosystems are phytoplankton and have lower mass than zooplankton.

the biomass of zooplankton is greater than that of phytoplankton and predatory fish are much larger than zooplankton; and

Marine pyramid of biomass is inverted because:

Biomass pyramid : It shows how much organic mass is within each trophic level.

The energy temporarily &#;trapped&#; within the mass of the trophic level is not counted.

Energy Pyramids : These show the proportion of energy passed from one trophic level to the next-level consumers in an ecosystem

Heterotrophs at all trophic levels have limited energy due to the low efficiency of solar energy conversion into carbon compound energy.

Photosynthesis uses only 3% of Earth's sunlight for land plants and 1% for aquatic plants.

Primary producers use some fixed energy for cellular respiration and tissue maintenance.

Gross primary production (GPP) : The rate at which plants capture and fix a given amount of chemical energy as biomass in a given length of time.

NPP is equal to the difference between the rate at which the plants produce useful chemical energy known as gross primary productivity (GPP) and the rate (R) at which they use some of that energy during respiration.

Net primary production (NPP) : The remaining fixed energy is the rate at which a ll the plants in an ecosystem produce net useful chemical energy.

Biodiversity is important because it helps keep the environment in a natural balance.

Large numbers of organisms of different species

Ecosystems that have high biodiversity are characterized by the following:

Ecosystem diversity : It describes the range of habitats that can be found in a specific area.

Species diversity : It is the number of different species that inhabit a specific area.

Genetic diversity : It describes the range of all genetic traits, both expressed and recessive, that make up the gene pool for a particular species.

It can be described and defined at the genetic, species, and ecosystem levels.

Biodiversity : The variability among species, between species, and of ecosystems.

Introduction of species from other areas

Extreme limitations in the supply of a fundamental resource

Require secondary and tertiary treatment methods for all water treatment plants; Use recycled water.

High nutrient levels or low dissolved oxygen levels resulting from water pollution can be lethal to some species.

Require package labeling for all products that use GMOs; Require that GMO crops be sterile; Require vigorous testing and research before allowing GMOs to be used

GMOs decrease the genetic variation necessary to cope successfully with changes in the environment.

Enforce international treaties that monitor and penalize countries that overfish; Establish quotas for all species fished; Have tighter enforcement of the Endangered Species Act.

It negatively impacts keystone species and threatens endangered species. Overfishing of lower-trophic-level species affects all organisms in the niche.

Modern industrial agriculture involves the use of one or two crops that cover massive areas of land.

It reduces the quality and quantity of suitable habitats for many species of flora and fauna

Enact carbon taxes; Require scrubbers for all industries that burn coal; Have tax incentives for products that do not require burning fossil fuels; Use renewable energy.

The acid rain produced from burning fossil fuels changes the pH of water habitats to the extent that many species cannot survive.

How the Activity can be Remediated

Minimum Viable Population Size : The number of individuals remaining after the bottleneck and how that compares to the smallest possible size at which a population can exist without facing extinction from a natural disaster.

As a result of the smaller population, there is less genetic diversity in the gene pool for future generations.

Population Bottleneck : It is a large reduction in the size of a single population due to a catastrophic environmental event.

Ex.: Giant Panda Bear : They survives almost entirely on bamboo and lives in remote bamboo forests in China.

Specialist Species : These species require unique resources and often have a very limited diet; they often need a specific habitat in which to survive.

Ex.: Raccoons : They are classified as omnivores as they are able to survive on a large variety of food types.

Generalist Species : Species that live in different types of environments and have varied diets.

If individuals are drawn from different environmental conditions or different habitats, the species richness can be expected to be higher than if all individuals are drawn from similar environments.

Species Richness : The number of different species (diversity) represented in an ecological community or region.

Reduces the need for fertilizers.

Allows for greater crop yields, which can feed more people.

Achieved in ecosystems through the actions of predators and parasites as well as by the defense mechanisms of their prey.

Reduces the need for pesticides

Keep pest populations in balance through natural predators.

Livestock provide different types of raw material such as fiber (wool), meat, milk

Larger islands have higher populations of species and therefore lower extinction rates.

Larger islands are bigger targets, so migrating species can find them more easily.

Island biogeography is used to predict biodiversity and extinction rates in habitat fragmentation on the continents.

Islands closer to the mainland have more biodiversity.

Habitat fragmentation is currently the main threat to terrestrial biodiversity.

Closer islands are also easier to find for migrating species.

Habitat fragmentation : It occurs when a habitat is broken into pieces by development, industry, logging, roads, etc., and can cause an edge effect.

Degree of Isolation : Distance to the nearest island or mainland.

Island Biogeography is influenced by the following:

Theory of Island Biogeography : It proposes that the number of species found on an &#;island&#; is determined by immigration and extinction of isolated populations.

Island Biogeography : It examines the factors that affect the richness and diversity of species living in these isolated natural communities.

Island : A suitable habitat for a specific ecosystem that is surrounded by a large area of unsuitable habitat.

Biological, climatic, and topographic factors affect an organism's abundance and distribution. If these exceed the organism's tolerance, species numbers will decline.

Each organism's success depends on a complex set of conditions, including minimum, maximum, and optimum environmental factors.

Law of Tolerance : It states that the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors within its environment.

Earth&#;s ecosystems are affected by both biotic and abiotic factors, and are regulated by the Law of Tolerance.

Natural and sudden disruptions dramatically affect which species will thrive in an environment and which species will not and will possibly become extinct.

Ecosystem : A community of organisms that interact with each other and their environment and that can change over time.

Burrows, dens, and nests can be destroyed by rushing water, forcing animals to move.

Flooding may also cause water and nutrients to run off across land surfaces.

Plant roots need oxygen, so saturated soils drown them.

Soil is no longer held in place by roots.

Sulfur gas and water in the atmosphere form microscopic droplets that stay in the atmosphere for years, cooling the troposphere by 2&#;3 degrees.

Volcanoes also contributed to a large portion of Earth&#;s early atmosphere.

Over 4.5 billion years, volcanoes and cooling magma condensed steam to create all of Earth's water.

Volcanic materials break down and weather to form some of Earth's richest soils, which have fed civilizations.

Soil is no longer held in place by roots.

Several plants actually require fire in their life cycles.

Ash and charcoal left from burnt vegetation can help add nutrients to depleted soil. These nutrients provide a rich environment for surviving vegetation and sprouting seeds.

Helps the ecosystem by clearing out dead and dying vegetation to give surviving plants more light.

Soil is no longer held in place by roots.

Episodic Process : Occurring occasionally and at irregular intervals. &#; El Niño and La Niña

~40% of sea-level change is due to coastal land subsidence (sinking).

~30% of sea-level change is due to thermal expansion&#;as the oceans warm (climate change), water expands.

~30% of sea-level change is due to the melting of glaciers and ice sheets on land.

The primary reason for changes in sea level today is glaciers and sea ice melts caused by global warming .

The temperature of ocean water, the amount of water retained in aquifers, glaciers, lakes, polar ice caps, rivers, and sea ice, the changing shape of ocean basins, tectonic uplift, and land subsidence all affect sea level.

Global sea level has changed significantly over Earth&#;s history, with sea level being affected by the amount and volume of available water and the shape and volume of the ocean basins.

Escaping natural disasters and their environmental aftermaths like wildfires, floods, and storm events.

Escaping harsh weather like seeking warmer water for breeding and raising young but returning to colder water for feeding as there is more food available.

Long-term adaptations may involve DNA changing over long time periods in response to natural selection involving evolutionary processes.

It is not inherited, nor does DNA change; and

Develops in response to temporary changes in the environment;

Physiological Adaptation : Such as methods of temperature control or how food is digested

Behavioral Adaptation : Such as instincts, mating behavior, or vocalizations.

Adaptation : The biological mechanism by which organisms adjust to new environments or to changes in their current environment.

Tolerance : When species are not affected by the presence of other species.

Inhibition : When one species modifies the environment to an extent that is not suitable for another species.

Facilitation : When one species modifies an environment to the extent that it meets the needs of another species.

Ecological succession : The gradual and orderly process of ecosystem development brought about by changes in community composition and the production of a climax community and describes the changes in an ecosystem through time and disturbance.

Since diversity is limited, ecosystem is subject to instability.

Because of nutrient sinks, nutrients may not be readily available to flow through cycles.

Because nutrient sinks have not fully developed, the nutrients are available to cycle through established biogeochemical cycles fairly rapidly.

Within the plant and top layers of soil.

In the soil and in leaf litter.

K-strategists: mature slowly; long-lived; number of organisms within a species is lower; greater biodiversity; niche specialists.

r-strategists: mature rapidly; short-lived species; number of organisms within a species is high; low biodiversity; niche generalists

Short. Not able to withstand wide environmental fluctuations.

Long. Seeds may become dormant and able to withstand wide environmental fluctuations.

These plant species appear only after macro-environmental changes, and after pioneer plant communities and after pioneer plant communities have adequately prepared the soil.

Early plants depend primarily on conditions created by macro-environmental changes

Since biomass is greater and more nutrients are contained within plant structures, nutrient cycling between the plant and soil tends to be slower.

High in tropics and wetlands; limited in deserts.

Secondary succession : A type of ecological succession in which plants and animals recolonize a habitat after a major disturbance.

Primary succession : The evolution of a biological community&#;s ecological structure in which plants and animals first colonize a barren, lifeless habitat.

Ecological succession : The process of change in the species structure of an ecological community over time, which can be millions of years in the case of primary succession or decades in the case of secondary succession.

Soil and some organisms are present

No soil at the beginning

Develops from previous occupants and from migrating species

Arrives from outside the area

Life has existed there before but disappeared due to natural disturbances

possibilities for new species to establish; and

Species-diversity increase continues until a balance is reached between:

NPP and GPP rise and then fall.

Early stages of succession have few species.

Biodiversity increases and then falls as the climax community is reached.

Changes that occur during succession include the following:

In later stages of succession near the climax community, gross productivity (GP) may be high, but increased respiration (R) balances it, so net productivity approaches zero and the gross production respiration (GP:R) ratio approaches 1:1.

In the early stages of succession , gross productivity is low due to the initial environmental conditions and low numbers of producers.

Species richness : The number of different species represented in an ecological community.

Species Richness generally increases as succession proceeds and generally peaks when it reaches the climax community, but the diversity growth rate gradually slows down as succession advances to the climax community.

Succession : A directional, non-seasonal, cumulative change in the types of plant species that occupy a given area over time, involving colonization, establishment, and extinction, shows how an ecosystem changes after an ecological disturbance.

The impact that a disturbance has on an ecosystem depends upon:

Ecological disturbance : An event or force that can result in mortality to organisms and changes in the spatial patterns in their ecosystem and plays a significant role in shaping the structure of individual populations within the ecosystem.

Sea stars prey on sea urchins, mussels, and other shellfish that have no other natural predators, keeping their populations in check.

Prairie dog burrowing aerates the soil and improves soil structure, while other animals use prairie dog burrows for shelter and hibernation.

Certain bat species pollinate critical trees in the rainforest and help disperse their seeds.

Keystone species : A species whose very presence contributes to a diversity of life and whose extinction would lead to the extinction of other forms of life.

Caddisflies, mayflies, and stoneflies require high levels of dissolved oxygen in the water

Indicator species : These are organisms whose presence, absence, or abundance reflects a specific environmental condition and can indicate the health of an ecosystem.

More likely to become extinct

Less likely to be extinct

Have an advantage when environmental conditions change

Less adaptable due to specialized needs

Able to use a variety of environmental resources

Tend to be predator and prey

Density-dependent limiting factors to population growth stem from intraspecific competition and include competition, predation, parasitism, and migration

Population size limited by density-independent limiting factors, including climate, weather, natural disasters, and requirements for growth

Have many offspring and tend to overproduce

Reproductive success : It is measured by how many organisms are able to mature and reproduce, with each survivorship curve representing a balance between natural resource limitations and interspecific and intraspecific competition.

Survivorship curves : It show age-distribution characteristics of species, reproductive strategies, and life history.

Death is prevalent for younger members of the species due to environmental loss and predation and declines with age.

Typical of species that have great numbers of offspring and reproduce for most of their lifetime.

Individuals in all age categories have fairly uniform death rates, with predation being the primary cause of death.

Death rates decrease in younger years due to advances in prenatal care, nutrition, disease prevention, and cures, including immunization.

Low mortality at birth with a high probability of surviving to advanced age.

Reproduction occurs fairly early in life, with most deaths occurring at the limit of biological life span.

Factors that keep population sizes in balance with the carrying capacity are called regulating factors and include the following:

It varies from species to species and is subject to changes over time. As an environment degrades, the carrying capacity decreases.

Carrying capacity (K) : It refers to the number of individuals that can be supported sustainably in a given area.

Uniform : Space is maximized between individuals to minimize competition.

Individuals are distributed randomly; occurs with dandelions and other plants that have wind-dispersed seeds.

There is little interaction among members of the population.

Random : Occurs in habitats where environmental conditions and resources are consistent.

Animals with inability of their offspring to independently move from their habitat.

Animals that work together to trap or corner prey.

Living in groups provides advantages and is common for animals.

Clumped : Some areas within a habitat are dense with organisms, while other areas contain few members.

Population dispersal pattern : It is how individuals or species of animal become distributed in different spaces over certain periods of time.

Environmental Resistance : Any factor that inhibits an increase in the number of organisms in the population.

Biotic potential : The maximum reproductive capacity of an organism under optimum environmental conditions.

Little or no suitable defense mechanisms against disease or parasites.

This point of stabilization is known as the carrying capacity of the environment , and it denotes the point at which the upward growth curve begins to level out

This type of population growth is termed &#;density dependent&#; since the growth rate depends on the number of organisms in the population.

This slowing of the growth rate reflects the increasing environmental resistance, which becomes proportionately more significant at higher population densities.

S-Curve : It occurs when, in a new environment, the population density of an organism initially increases slowly but then stabilizes due to the finite amount of resources available.

This type of population growth rate is known as &#;density dependent,&#;a the regulation of the growth rate is not tied to the population density until the resources are exhausted and the population growth crashes.

J-Curve : It represents a population growth occurs in a new environment when the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance or another factor suddenly impacts the population growth.

More prey means more energy for predators, which leads to more predators and fewer prey.

Predators and prey maintain population stability by keeping animal populations within the carrying capacity of their environment.

Limiting factors can cause a negative feedback loop because populations cannot exceed the ecosystem's carrying capacity.

When part of the system increases, another part of the system also changes in a way that makes the first part increase even more.

Positive feedback loops stimulate change and are responsible for sudden or rapid changes within ecosystems.

Density-independent factors : These are factors that limit the size of a population, and their effects are not dependent on the number of individuals in the population.

Density-dependent limiting factors : These are factors whose effects on the size or growth of the population vary with the density of the population.

Based on Liebig&#;s law of the minimum , even if all other factors are favorable, the one that is least favorable will dictate the growth, abundance, or distribution of the population of a species.

Limiting Factor : It can be any resource or environmental condition that limits the abundance, distribution, and/or growth of a population.

The larger the growth rate (r), the faster the doubling time.

Key points to remember about population doubling times are as follows:

To find how long it takes for a population to double in size we can use the following formula: dt= 70/r

Doubling time : It is the amount of time it takes for a population to double in size.

Rule of 70 : It helps to explain the time periods involved in exponential population growth occurring at a constant rate.

Percent Rate of Change = [(new # - old #)/old #] × 100

As a country's population grows, wealth must be redistributed, lowering GDP per capita.

Due to government priorities, financial constraints, and special interest groups, rapid population growth can make it politically difficult for countries to raise living standards and protect the environment.

Tobacco-related diseases kill more people than AIDS, tuberculosis, road accidents, murder, and suicide combined.

Heavy metals and other contaminants also cause widespread health problems.

Air pollution kills nearly three million more.

Over 12 million people die each year from dirty water and poor sanitation, mostly in developing nations.

If the global temperature rises as predicted, sea levels will rise by several meters, causing widespread flooding, droughts, and agricultural disruption.

Earth&#;s surface is warming due to greenhouse gas emissions, largely from burning fossil fuels.

The demand is soaring as the population grows and per-capita use rises.

The supply of freshwater is finite.

Population pressures have degraded two billion hectares of arable land&#;the size of Canada and the US combined.

In 64 of 105 developing countries, especially in Africa, Asia, and parts of Latin America, population growth has outpaced food supply.

25% of the world is malnourished.

However, demand for forest products may exceed sustainable consumption by 25%.

Forests sustain ecosystems and contribute $400 billion to the global economy.

Nearly half of the world's original forest cover has been lost, and 16 million hectares are cut, bulldozed, or burned annually.

Ocean fisheries are overexploited, estuaries (sea nurseries) are being drained and filled in due to population growth, and fish catches are down.

Yet, two-thirds of the world's species are in decline due to human activity.

Urn-Shaped age-structure diagram : It indicates that the post-reproductive group is largest and the pre-reproductive group is smallest, a result of the birth rate&#;s falling below the death rate, and is characteristic of declining populations

This is characteristic of stable populations.

Bell shape age-structure diagram : It indicates that pre-reproductive and reproductive age groups are more nearly equal, with the post-reproductive group being smallest due to mortality.

Pyramid-shaped age-structure diagram : It indicates that the population has high birth rates and the majority of the population is in the reproductive age group

Age-structure diagrams : These are determined by birth rate, generation time, death rate, and sex ratios.

Urbanization results in a higher cost of living and reduces the need for extra children to work on farms.

There is greater personal acceptance and government encouragement of contraception.

The number of females in the workforce has increased.

More individuals desire to increase their standard of living by having fewer children.

Many &#;millennials&#; are postponing marriage until their careers are established.

As developing countries transition to developed countries, there is greater access to primary healthcare and family-planning services.

Declines in fertility rates can be attributed to several factors, as follows:

Total fertility rate (TFR) : The average number of children that each woman will have during her lifetime.

The industrial and medical revolutions (within the last ~ 200 years).

The first agricultural revolution, which allowed the change from hunting and gathering to crop growing (~ 10,000 B.C.E.)

The use of tools (3.5 million years ago)

The human population has had four surges in growth as a result of the following:

Improvements in the safety of water supplies

Improvements in medical and public health programs, resulting in better access to anesthetics, antibiotics, and vaccinations

Increased food and more efficient distribution, resulting in better nutrition

Several factors have reduced human death rates, as follows:

We should promote Earth-sustaining economic growth and learn from nature how Earth sustains itself.

Earth Wisdom : Beliefs that nature exists for all Earth&#;s species and we are not in charge of Earth; resources are limited and should not be wasted.

Estimates are as high as 9.8 billion.

Our success depends on how well we manage Earth&#;s life-support systems mostly for our own benefit.

The potential for economic growth is essentially unlimited.

We will not run out of resources because of our ability to develop and find new ones.

Planetary Management : Beliefs that as the planet&#;s most important species, we are in charge of Earth.

Healthcare, health insurance, vaccines, medical cures, preventative care, advanced drugs and antibiotics, hygiene and sanitation, agriculture and distribution, and education have increased growth.

In C.E., the growth rate was ~ 0.1%.

Up to 25% mortality rates are attributed to the plagues that reached their peak in the mid-s.

Factors that reduced population growth rate during this time were famines, wars, and disease

Population rate increased during the Middle Ages because new habitats were discovered.

Frontier Worldview : Viewed undeveloped land as a hostile wilderness to be cleared and planted, then exploited for its resources as quickly as possible.

Rate of population growth during this period was about 0.03 to 0.05%, compared with today&#;s growth rate of 1.3%.

Increases due to advances in agriculture, domestication of animals, and the end of a nomadic lifestyle.

Earth Wisdom : Natural cycles that can serve as a model for human behavior.

Unless mass immigration continues, population aging and decline will occur in this stage.

Death rates exceed birth rates in most European and East Asian nations.

Some theorists believe a fifth stage is needed to represent countries with sub-replacement fertility.

In some countries, birth rates are lower than mortality rates, resulting in population losses.

The standard of living is higher, and birth and death rates are low.

Population growth is zero when birth and death rates are equal.

Economic pressures lower the birth rate until it approaches the death rate.

Retirement safety nets reduce parents' need for more children.

Leisure time and food are not priorities.

Urban families are increasingly discouraged from having large families as costs rise.

Hygiene, medical advances, sanitation, cleaner water, vaccinations, and higher education lower the death rate, resulting in a significant population increase.

This stage occurs after the start of industrialization.

Since , drug therapy has reduced new infections by 28% and death rates by 44% in the region.

Sub-Saharan Africa has 54% of the world's AIDS-HIV cases but only 6% of the population.

Poor agricultural practices, pestilence, and living conditions make food scarce and medical care is poor.

Demographic transition : It is the transition from high birth and death rates to lower birth and death rates as a country or region develops from a pre-industrial to an industrialized economic system.

Plate tectonic theory : It states that Earth&#;s lithosphere is divided into a small number of plates that float on and travel independently over the mantle, with much of Earth&#;s seismic activity occurring at the boundaries of these plates.

Tropical regions on some continents had polar climates in the past, based on paleo-climatic data.

The continents fit together like pieces of a puzzle.

Similarities existed in rocks between the east coasts of North and South America and the west coasts of Africa and Europe.

Glaciated landscapes occurred in the tropics of Africa and South America.

Fossils of extinct land animals were found on separated landmasses.

He based his theory on the following six factors:

Wegener believed that this supercontinent began to break up into smaller continents around 200 million years ago.

In , Alfred Wegener proposed that all present-day continents originally formed one landmass he called Pangaea .

Subduction zones : These are areas on Earth where two tectonic plates meet and move toward each other, with one sliding underneath the other and moving down into the mantle.

When one plate moves beneath another (subduction) or when two plates converge, it can result in earthquakes and volcanoes.

The lithosphere is the solid, outer part of the Earth and is broken into huge sections called plates , which are slowly moving.

Dating of the rocks indicated that as one moved away from the ridge, the rocks became older, and suggested that new crust was being created at volcanic rift zones.

Similar patterns were discovered on either side of mid-oceanic ridges found near the center of the oceanic basins.

During the s, alternating patterns of magnetic properties were discovered in rocks found on the seafloor.

The friction and stress buildup from the sliding plates frequently causes earthquakes, a common feature along transform boundaries.

Transform boundaries : These occur where plates slide past each other in opposite directions.

When two continental plates collide, mountain ranges are created as the colliding crust is compressed and pushed upward.

A deep undersea trench is located in front of such arcs where the descending plate dips downward.

Their curve is generally convex toward the open ocean.

They are created by subduction processes and occur on the continental side of the subduction zone.

When two oceanic plates converge, they create an island arc &#; a curved chain of volcanic islands rising from the deep seafloor and near a continent.

It can create massive fault zones in the oceanic ridge system and areas of frequent oceanic earthquakes.

Divergent Boundaries : These occur when two plates slide apart from each other.

When a denser oceanic plate subducts a less dense continental plate, an oceanic trench may form on the ocean side and a mountain range on the continental side.

an orogenic belt, if the two plates collide and compress.

a subduction zone, where one plate moves underneath the other; or

Convergent Boundaries : These occur where two plates slide toward each other.

Topography : Refers to the physical characteristics of the location.

Parent material : Refers to the rock and minerals from which the soil derives. The nature of the parent rock, which can be either native to the area or transported to the area by wind, water, or glacier, has a direct effect on the ultimate soil profile.

Living organisms : Include the nitrogen-fixing bacteria Rhizobium, fungi, insects, worms, snails, etc., that help to decompose litter and recycle nutrients.

Climate : Measured by precipitation and temperature, which results in partial weathering of the parent material, which forms the substrate for soil.

Soils develop in response to the following factors:

Subsoil : Tends to be yellowish in color due to the accumulation of iron, aluminum, humic compounds, and clay leached from A and E horizons.

Topsoil : Organic matter, living organisms, and inorganic materials; it is very thick in grass lands.

Organic materials from the remains of dead plants and animals

Open spaces that can be filled with air or water

Soils are composed of three main ingredients:

This thin layer is a basic, natural resource, and its characteristics deeply affect every other part of the ecosystem.

Soils : These are a thin layer on top of most of Earth&#;s land surface.

Removing crop wastes instead of plowing the organic material back into the soil

Poor agricultural techniques that lead to soil erosion include the following:

It decreases the soil&#;s water-holding capacity, destroys the soil profile, and increases soil compaction.

Soil erosion : It is the movement of weathered rock and/or soil components from one place to another caused by flowing water, wind, and human activity.

Steep slopes and areas at the bottom of slopes or canyons

Slopes that have been altered for the construction of buildings and roads

Areas where wildfires or construction have destroyed vegetation

Areas where landslides have occurred before

Some areas are more likely to experience landslides or mudslides, including the following:

It usually begin on steep slopes and can be triggered by natural disasters in areas where wildfires or construction have destroyed vegetation.

Mudslides : It is also known as debris flows or mudflows, are a common type of fast-moving landslide that tends to flow in channels.

These occur when water rapidly collects in the ground, causing a surge of water-soaked rock, earth, and debris. They can occur after heavy rains, droughts, earthquakes, or volcanic eruptions.

Landslides : These occur when masses of rock, earth, or debris move down a slope.

Sedimentary : These are formed by the piling and cementing of various materials over time in low-lying areas.

Metamorphic Rocks : These are formed by intense heat and pressure, high quartz content.

Igneous rocks are broken down by weathering and water transport.

Extrusive igneous rocks : Solidify on or near the surface, cool quickly, and have a fine-grained smooth texture.

Igneous Rocks : These are formed by cooling and classified by their silica content.

Forms large, dense clumps when wet. Low permeability to water; therefore, upper layers become waterlogged.

Sedimentary material consisting of very fine particles between the sizes of sand and clay.

Holds water but does not become waterlogged. Particle size can vary.

About equal mixtures of clay, sand, silt, and humus. Rich in nutrients.

Good for crops and plants requiring low amounts of water.

Water flows through too quickly for most crops.

Soil containing humus will crumble, allowing air and water to move easily through the loose soil, making root growth easier, reducing erosion, and stabilizing the pH.

Earthworms often help mix humus with minerals in the soil.

As this material decays, it breaks down into its most basic chemical elements and compounds, which are important nutrients for plants and animals that depend upon soil for life.

The thick brown or black substance that remains after most of the organic litter has decomposed

Humus: It is the dark organic material that forms in soil when plant and animal matter decays.

Formula: Where Vw is the volume of the water required to saturate the soil and Vt is the total volume of the saturated soil (1 cm³ = 1 mL).

After the soil is saturated with water, all of the excess water and some of the nutrients and pesticides that are in the soil solution are leached downward in the soil profile.

Soil texture: A reflection of the particle size distribution of soil.

Water holding capacity : It is controlled primarily by the soil texture and the soil organic matter content.

The particles which constitute the inorganic portion of soil and which are 2 mm or less in diameter.

Size of soil and particles : It determines the amount of moisture, nutrients, and oxygen that the soil can hold along with the capacity for water to infiltrate.

It determines how much water, air, and nutrients are available for plant roots.

Acidic soils can be caused by pollutants, such as acid rain and mine spoiling, and are most often found in areas of high rainfall.

Various plants have different soil pH requirements.

pH : It is the measure of how acidic or basic soil is.

Permeability : The measure of the capacity of the soil to allow water and oxygen to pass through it.

The capacity to hold and retain nutrients is greatly reduced in highly weathered soils since most nutrients have been lost due to leaching.

As these particles decrease in size, the soil is able to retain greater amounts of nutrients.

Initially, as soil particles begin to weather, primary minerals release nutrients into the soil.

The process of weathering greatly influences the availability of plant nutrients.

Nutrient-Holding Capacity : The ability of soil to absorb and retain nutrients so they will be available to the roots of plants.

Heavily compacted soils contain few large pores and have a reduced rate of both water infiltration and drainage from the compacted layer.

Degree of Soil Compaction : It is measured by dry unit weight and depends on the water content and compaction effort.

When there&#;s little or no light, plants require oxygen to break down the plant&#;s sugar(s) to release CO2, water, and energy.

This helps the roots grow deeply and produce a stronger, more vigorous plant.

Aeration, which reduces soil compaction, involves perforating the soil with small holes to allow air (especially oxygen), water, and nutrients to penetrate to the roots.

Aeration : Refers to how well a soil is able to absorb oxygen, water, and nutrients.

Soil Food Web: It is the community of organisms living all or part of their lives in the soil, and it describes a complex living system in the soil and how it interacts with the environments, plants, and animals.

Increased oxygen concentrations allowed biological diversification and major chemical changes between Earth's clay, rocks, and sand, atmosphere, and oceans.

Free oxygen oxidized atmospheric methane (GWP 25) to carbon dioxide (GWP 1), weakening Earth's greenhouse effect and causing planetary cooling and ice ages.

As oxygen began to accumulate in the atmosphere, it is believed that there were two major consequences:

It was a time period when the Earth&#;s atmosphere and the shallow ocean experienced a rise in oxygen.

Great Oxidation Event (GOE) 2.5 billion years ago killed almost all life on Earth.

Atmospheric carbon dioxide (CO2) produced by volcanoes and methane (CH4) produced by early microbes, both greenhouse gases, likely produced a strong greenhouse effect and allowed the earliest life forms to develop.

Average lifetime of a CO2 molecule in the atmosphere is ~100 years.

Produced during cellular respiration, the combustion of fossil fuels, and the decay of organic matter.

Besides evaporation, other sources of atmospheric water include combustion, respiration, volcanic eruptions, and the transpiration of plants.

Largest amounts are found near the equator, over oceans, and in tropical regions.

Product in photosynthesis and reactant in cellular respiration.

Free elemental oxygen (O2) began to accumulate in the atmosphere about 2.5 billion years ago.

The most abundant element by mass in Earth&#;s crust, making up almost half of the crust&#;s mass as silicates.

By mass, the third most abundant element in the universe, after hydrogen and helium.

Returns to the atmosphere through combustion of biomass and denitrification.

Deposits on Earth through nitrogen fixation and reactions involving lightning and subsequent precipitation.

Makes up about 3% of the human body by weight.

Found in all organisms, primarily in amino acids and nucleic acids.

Temperature increases with altitude in the stratosphere.

In the stratosphere, ozone (O3) absorbs high-energy ultraviolet radiation from the sun and is broken down into atomic oxygen (O) and diatomic oxygen.

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Stratosphere : It is located 6&#;30 miles (10&#;50 km) above Earth&#;s surface.

The atmospheric pressure within the troposphere is highest at the surface and decreases with height, whereas the temperature of the troposphere decreases with height.

75% of the atmosphere&#;s mass and almost all of the water vapor on the planet is contained within the troposphere, with weather also occurring in this layer.

Troposphere : The lowest portion of Earth&#;s atmosphere, 0&#;6 miles (0&#;10 km) above Earth&#;s surface.

Heat Index (HI) : The measure of how warm it feels when factoring in relative humidity.

Air rises when it becomes warmer and less dense than the air above it, creating pressure differences that cause wind.

Convection : It is the primary way energy is transferred from hotter to colder regions in Earth&#;s atmosphere and is the primary determinant of weather patterns.

The statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years.

Climate : The average weather conditions prevailing in an area in general or over a long period.

It influences the following physical properties:

It describes whatever is currently happening outdoors.

Weather : It is caused by the movement or transfer of heat energy, which results from the unequal heating of Earth&#;s surface by the sun.

Climate and Factors that Influence it

Volcanic aerosols injected into the stratosphere can also provide surfaces for ozone-destroying reactions.

Volcanic aerosols : These exist in the atmosphere for an average of one to three years.

Sulfur-rich volcanic eruptions : It can eject material into the stratosphere, potentially causing tropospheric cooling and stratospheric warming.

At night, heat escapes from Earth&#;s surface, and daily minimum temperatures occur just before sunrise.

Rotation : Daily temperature cycles are primarily influenced by Earth&#;s rotation on its axis.

Pollution : Greenhouse gases are emitted from both natural sources and anthropogenic sources.

Moisture Content of Air : It is a primary determinant of plant growth and distribution and is a major determinant of biome type.

Climate is influenced by the location of high and low air pressure zones and where landmasses are distributed.

At the poles, the sun&#;s rays strike Earth at an acute angle, which spreads the heat over a larger area.

The farther away from the equator, the less sunlight is available.

Latitude : The measurement of the distance of a location on Earth from the equator.

Climate is also influenced by urbanization and deforestation.

Increased pollution alone tends to increase the amount of rainfall in urban areas by as much as 10% when compared with undeveloped areas.

Human Activity and Climate : Climate can also be influenced by human activity.

Heat : Climate is influenced by how heat energy is exchanged between air over the oceans and the air over land.

If taken too far, however, Earth could evolve into a hothouse.

The most important greenhouse gases are water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).

Greenhouse Effect : Without this effect, Earth would be cold and inhospitable.

Stationary Front : A pair of air masses, neither of which is strong enough to replace the other, that tend to remain in essentially the same area for extended periods of time.

Warm Front : The boundary between an advancing warm air mass and the cooler one it is replacing.

Cold Front : The leading edge of an advancing mass of cold air and is associated with thunderhead clouds, high surface winds, and thunderstorms.

The air masses can vary in temperature, dew point and wind direction.

Fronts : When two different air masses meet, the boundary between them forms a &#;front.&#;

Because of this, changes in temperature are more extreme in the middle of the continents than on the coasts.

Distance to Oceans : Oceans are thermally more stable than landmasses; the specific heat of water is five times greater than that of air.

Carbon Cycle : The process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere.

Snow and ice have the highest albedo.

Materials like ocean water have low albedo, whereas landmasses have moderate albedo.

Albedo : An expression of the ability of surfaces to reflect sunlight.

These can be categorized as equatorial, tropical, polar, Arctic, continental, or maritime.

Air Mass : A large body of air that has similar temperature and moisture content.

Sea Breeze : It occurs during relatively calm, sunny days, the land warms up faster than the sea, causing the air above it to become less dense.

Land Breeze : It occurs during relatively calm, clear nights when the land cools down faster than the sea, resulting in the air above the land becoming denser than the air over the sea.

Coriolis Effect : A phenomenon wherein earth&#;s rotation on its axis causes winds to not travel straight, which causes prevailing winds in the Northern Hemisphere to spiral clockwise out from high-pressure areas and spiral counterclockwise toward low-pressure areas.

Wind Direction : It is based on the direction from which wind originated.

The greater the pressure difference is, the greater the wind speed.

Wind Speed : It is determined by pressure differences between air masses.

It have been used by captains of sailing ships to cross the world&#;s oceans.

Trade Winds : These are the prevailing pattern of easterly surface winds found in the tropics near Earth&#;s equator, within the troposphere or lower portion of Earth&#;s atmosphere.

Cool, dense air descends toward Earth's surface and warms in high-pressure masses, which are usually associated with fair weather.

They blow clockwise north of the equator and counterclockwise south of it, with air from higher in the atmosphere sinking down to fill the gaps left by outward-blowing air.

High-pressure weather systems : They have higher pressure at their center than around them, so winds blow away from them.

Low-pressure weather systems have lower pressure at their centers than elsewhere.

Air closer to Earth's surface is warmer and rises due to Earth's rotation on its axis, revolution around the sun, and tilt.

The climate is characterized by warm to hot summers and mild winters. The tropical wet and dry (or savanna) climate has a dry season more than two months long.

Subtropical regions of the Hadley cell are characterized by low relative humidity, little cloud formation, high ocean evaporation due to the low humidity, and many of the world&#;s deserts.

The equatorial regions of the Hadley cells are characterized by high humidity, high clouds, and heavy rains.

Surface air from subtropical regions returns toward the equator to replace the rising air.

After cooling in the upper atmosphere, the air sinks back to Earth&#;s surface within the subtropical climate zone.

Air heated near the equator rises and spreads out north and south.

Climates of the middle latitudes have a distinct winter season.

Defined seasons are the rule, with strong annual cycles of temperature and precipitation.

Mid-latitude climates can have severe winters and cool summers due to mid-latitude cyclone patterns.

The descending winds of the Hadley cells diverge as moist tropical air moves toward the poles in winds known as the westerlies.

Ferrel cells develop between 30° and 60° north and south latitudes.

The amount of snowfall per year is relatively small.

Very little water exists in this area because it is tied up in the frozen state as ice.

Sinking air suppresses precipitation. As a result, the polar regions are deserts.

This air meets with the warm tropical air from the mid-latitudes and then returns to the poles, cooling and then sinking.

Polar cells originate as icy-cold, dry, dense air that descends from the troposphere to the ground.

There is also a relationship between the chemistry of the Antarctic polar vortex and severe ozone depletion.

Due to the equator-pole temperature difference, these cold, low-pressure areas strengthen in winter and weaken in summer.

The bases of the two polar vortices are located in the middle and upper troposphere and extend into the stratosphere.

Polar Vortex : A low-pressure zone embedded in a large mass of very cold air that lies atop both poles.

These storms produce strong winds that push the seawater toward the shore, which often leads to flooding.

Storm Surge: A rise in sea level that occurs during tropical cyclones, typhoons, or hurricanes.

In the center of the hurricane is the eye , an area of descending air and low pressure.

This cyclonic circulation allows them to pick up moisture and latent heat energy from the ocean.

Hurricane development requires tropical ocean thunderstorms and cyclonic circulation that starts to rotate them.

A subtropical high-pressure zone creates hot daytime temperatures with low humidity that allow for large amounts of evaporation, with the Coriolis effect initiating the cyclonic flow.

Hurricanes begin over warm oceans in areas where the trade winds converge.

Cyclones : Term used in South Pacific and Indian Ocean.

Hurricanes : Term used in the Atlantic and Northeast Pacific.

Hurricanes, cyclones, and typhoons are all the same weather phenomenon.

The funnel, made up of dust, air, and debris, reaches the ground, and a tornado is formed.

The mesocyclone meets warm air moving up and cold air moving down and creates a funnel.

The strong winds begin to rotate (due to updrafts and downdrafts) and form a column of spinning air called a mesocyclone.

The center of the tornado is an area of low pressure.

Tornadoes : These are wirling masses of air with wind speeds close to 300 miles per hour (485 kph).

Typically last less than an hour

Require very low values of vertical shear in order to form and grow

Monsoons blow from the land toward the sea in winter and from the sea toward land in the summer.

Monsoon winds: These blow from cold to warm regions because cold air takes up more space than warm air.

Monsoons : These are strong, often violent winds that change direction with the season.

Watershed management : It reduces pesticides and fertilizers that wash off farm fields and into nearby waterbodies by using land, forest, and water resources in ways that don't harm plants and animals.

Mississippi River watershed : The largest watershed in the United States, which drains more than one million square miles or land.

Watershed : A land area that drains rainfall and snowmelt into a lake, ocean, or aquifer.

Sunlight shining on Earth at a lower angle spreads its energy over a larger area, making it weaker than if the sun were higher overhead.

Seasonal changes in the angle of sunlight are caused by the tilt of Earth&#;s axis, which is the basic mechanism that results in warmer weather in summer than in winter.

The angle at which sunlight strikes Earth varies by location, time of day, and season due to Earth&#;s orbit around the sun and its rotation around its tilted axis.

The amount of heat energy received at any location on Earth is a direct effect of the angle of the sunlight reaching the Earth&#;s surface.

Earth&#;s rotation on its axis (once every 24 hours)

Earth&#;s rotation around the sun (once per year)

Factors that affect the amount of solar energy at the surface of Earth (which directly affects plant productivity) include the following:

Warm, moist ocean air is a driving force for precipitation patterns around the world as it is carried over cooler land masses.

Large water bodies also tend to stabilize the climate of adjacent land masses by absorbing extra heat during warm periods and releasing it during cooler periods.

Oceans and lakes store solar radiation (heat), and as the water heats up it adds moisture to the air above it, beginning a process that drives the major air currents around the world.

Over 70% of the Earth&#;s surface is covered in water.

Tropic of Capricorn : The southernmost latitude reached by the overhead sun.

Tropic of Cancer : The northernmost latitude reached by the overhead sun.

Latitude : A measure of distance either north or south from the equator.

Many high-altitude plains are technically deserts because they are on the downwind (leeward) side of a mountain range or continental mass.

Higher elevations have lower air pressure due in part to there being fewer atoms and molecules per unit of air and, thus, cooler temperatures.

Climates become cooler and the cold season lasts longer as elevation increases.

Rain Shadow Effect : The drier situation which is directly responsible for the plants that grow there, which in turn affects the animals that live there.

The mountain range's leeward side is drier than the windward side because air on this side has less moisture.

The cooled air can't hold as much water anymore, so it rains on the side of the mountain range that faces the wind.

When an air mass hits mountains, it slows down and cools because the air is forced up into cooler parts of the atmosphere to move over the mountains.

Mountain ranges : These are barriers to the smooth movement of air currents across continents.

It is caused by winds pulling nutrient-rich water from below, increasing fishing stocks in this shallow eastern thermocline (90 feet or 30 m).

Upwelling : It occurs when prevailing winds, produced through the Coriolis effect and moving clockwise in the Northern Hemisphere, push warmer, nutrient-poor surface waters away from the coastline

The trade winds, in piling up water in the western Pacific, make a deep warm layer in the west that pushes the thermocline down while it rises in the east.

The ocean is generally around 24 inches (60 cm) higher in the western Pacific, and the water there is about 14°F warmer.

During normal conditions, easterly trade winds move water and air toward the west.

Increased ocean warmth enhances convection, which then alters the jet stream

Effects are strongest during the Northern Hemisphere winter because ocean temperatures worldwide are at their warmest.

A band of warmer-than-average ocean water temperatures develops off the Pacific coast of South America.

As a result, the thermocline off western South America becomes deeper and there is a decrease in the upwelling of nutrients, which causes extensive fish kills.

This causes the normal flow of water away from western South America to decrease &#;pile up.&#;

The southeastern US has warmer winters and the northwest cooler ones, while India and southeast Asia have heavier monsoons.

This then results in an increase in the number of hurricanes.

This then results in wetter-than-normal conditions across the Pacific Northwest, and both drier- and warmer-than-normal conditions in the southern United States.

This then results in cooler-than-normal sea surface temperatures off of South America.

This then results in an increase in the upwelling off of South America.

Trade winds that blow west across the tropical Pacific are stronger than normal.

An increase in rainfall may result in an increase in flooding, soil erosion, and leaching of nutrients from the soil.

Increase or decrease in the amount of normal rainfall

Ocean currents and glacial melting may change with warmer ocean temperatures.

Hurricanes and tornadoes may become stronger and more frequent.

Global warming decreases as warmer ocean water can hold less CO2.

Marine food webs and biodiversity may be disrupted by species that cannot tolerate warmer or cooler water temperatures.

Changes in weather patterns may increase insect-borne diseases.

5.1: The Tragedy of the Commons

Controlling some "commons" is easier than others. Air and the open oceans are harder to control than land, lakes, rangeland, deserts, and forests.

Investors would be encouraged to pay a short-term price for a long-term gain by including discount rates in resource valuation.

Different standards and practices on one parcel may or may not affect all parcels. Environmental decisions are long-term, while economic decisions are short-term.

Limits to &#;The Tragedy of the Commons&#; include the following:

Over-extraction of groundwater and wastewater due to excessive irrigation

Frontier logging of old-growth forests and the practice of &#;slash and burn&#;

The following environmental issues echo "The Tragedy of the Commons" sustainability issues:

The seas, air, water, animals, and minerals are all &#;the commons&#; and are for humans to use, but those who exploit them become rich.

The essay parallels what is happening worldwide in regards to resource depletion and pollution.

Garrett Hardin wrote &#; The Tragedy of the Commons &#; in .

Increasing habitat fragmentation and CO2 emissions from burning and tree decay.

Impacts of deforestation include the following:

Deforestation : It is the conversion of forested areas to non-forested areas, which are then used for grain and grass fields mining, petroleum extraction, fuel wood cutting, commercial logging, tree plantations, or urban development.

Tree canopies : It provide the ground below with shade and maintain a cooler and moister environment below.

Forest edges : These are created when trees are harvested, particularly when they are clear-cut.

Edge Effect : It refers to how the local environment changes along some type of boundary or edge.

Temporary wood availability followed by long periods without wood Reduction in long-term and short-term carbon sinks, which increases atmospheric CO2

Allows sunlight to reach the ground, making it warmer and drier, unsuitable for many forest plants.

Environmental impacts of clear-cutting include the following:

Clear-cutting : It occurs is when all of the trees in an area are cut at the same time.

Reducing or eliminating the practice of clear-cutting.

Educating farmers about sustainable forest practices and their advantages.

Scientific farming methods such as biotechnology, genetic engineering, and the use of pesticides are now beginning to focus on more sustainable methods.

Mechanization such as tractors and combines requires less labor and makes food prices more affordable.

The invention of the tractor, combined with other farm machinery, improved efficiency on farms.

The invention of the seed drill allowed farmers to avoid wasting seeds and to plant in rows.

New crops came into Europe from trade with the Americas.

New banking and lending practices helped farmers afford new equipment and seed.

Increased agricultural output made it possible to feed large, urban populations.

Occurred at the same time as the Industrial Revolution&#;mechanization had a major role in this revolution and changed the way people farmed.

Settled communities permitted people to observe and experiment with plants to learn how they grow and develop.

People went from hunting and gathering to the domestication of plants and animals, which allowed people to settle in areas and create cities.

BT corn and Golden Rice, modified with daffodil genes to produce more beta-carotene (converts to Vitamin A), are examples (corn modified with a bacterial insecticide gene that produces insect toxins within the cells of the corn).

This revolution saw the development and spread of genetically modified organisms (GMOs)&#;animals, plants, and microorganisms&#;with genes that don't exist in nature.

In the mid-s, new engineering techniques and free-trade agreements involving food production property rights shaped agricultural policies and food production and distribution systems worldwide.

The introduction of inorganic fertilizers, synthetic pesticides, new irrigation methods, and disease-resistant, high-yielding crop seeds.

Tillage : An agricultural method in which the surface is plowed and broken up to expose the soil, which is then smoothed and planted.

Waterlogging : Saturation of soil with water, resulting in a rise in the water table.

Salinization : Water that is not absorbed into the soil evaporates, leaving behind dissolved salts in topsoil.

Desertification : Productive potential of arid or semiarid land falls by at least 10% due to human activity and/or climate change.

Soil degradation : It is the decline in soil condition caused by its improper use or poor management, usually for agricultural, industrial, or urban purposes.

Soil Erosion : It is the movement of weathered rock or soil components from one place to another and is caused by flowing water, wind, and human activity.

Slash-and-Burn Agriculture : It is a widely used method of growing food or clearing land in which wild or forested land is clear-cut and any remaining vegetation is burned.

These are managed through livestock grazing and prescribed fire rather than more intensive agricultural practices of seeding, irrigation, and the use of fertilizers.

Rangelands : These are native grasslands, woodlands, wetlands, and deserts that are grazed by domestic livestock or wild animals.

Genetic engineering techniques: These allow for the introduction of new traits as well as greater control over traits when compared to previous methods.

Genetically modified foods : These are foods produced from organisms both animal and plant) that have had changes introduced into their DNA.

Organic Fertilizers: Any Any fertilizer that originates from an organic source, such as bone meal, compost, fish extracts, manure, or seaweed.

Inorganic Fertilizers : A fertilizer mined from mineral deposits or manufactured from synthetic compounds.

Fertilizers : These provide plants with the nutrients needed to grow healthy and strong.

Overgrazing: A plant is considered overgrazed when it is re-grazed before the roots recover, which can reduce root growth by up to 90%.

Desertification : It is the conversion of marginal rangeland or cropland to a more desert-like land type.

As farms become more efficient, they are able to produce more products at a lower cost, which tends to stabilize food prices and make more food available to more people, which is vital for developing countries.

Agricultural productivity: It implies greater output with less input.

Spray: Uses overhead sprinklers, sprays or guns to spray water onto crops.

Water is applied to the top of each furrow and flows down the field under gravity, infiltrating the ground more at the beginning and less at the end.

Furrow (Channel) : Small parallel channels are dug along the field length in the direction of the predominant slope.

Being simple and inexpensive, it is the method most widely used in less-developed countries.

Flood : Water is pumped or brought to the fields and is allowed to flow along the ground among the crops.

Drip : Water is delivered at the root zone of a plant through small tubes that drip water at a measured rate.

Siphon tubes are used to move the water from the main ditch to the canals.

The plantings are watered by placing canals or furrows in between the rows of plants.

Ditch : Dug and seedlings are planted in rows.

Irrigation : The application of controlled amounts of water to plants at needed intervals and has been a necessary component of agriculture for over 5,000 years.

Integrated Pest Management (IPM): It is an ecologically based approach to control pests.

Pesticides : These can be used to control pests, but their use has drawbacks.

Organophosphates : These are extremely toxic but remain in the environment for only a brief time.

Organic pesticides : These are natural poisons derived from plants such as tobacco or chrysanthemum.

Inorganic pesticides : These are broad-based pesticides that include arsenic, copper, lead, and mercury. They are highly toxic and accumulate in the environment.

Fumigants : These are used to sterilize soil and prevent pest infestation of stored grain.

Carbamates: Also known as urethanes, affect the nervous system of pests, which results in the swelling of tissue in the pest.

Persistent organic pollutants (POPS): These organic compounds can pass through and accumulate in living organisms' fatty tissues because they don't break down chemically or biologically.

Pesticide Treadmill : Also known as pest traps; farmers are forced to use more and more toxic chemicals to control pesticide-resistant insects and weeds.

In response to resistance, farmers may increase pesticide quantities and/or the frequency of pesticide applications, which magnifies the problem.

Pesticide resistance : It describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest.

The destruction of beneficial and non-targeted organisms.

Genetic resistance : An inherited change in the genetic makeup of the pests that confers a selective survival advantage.

Pests&#; becoming resistant to a particular pesticide

When used effectively, IPM can reduce the following:

Regular monitoring through visual inspection and traps followed by record keeping

Polyculture : The simultaneous cultivation or raising of several crops or types of animals

Intercropping : A farming method that involves planting or growing more than one crop at the same time and on the same piece of land.

Developing genetically modified crops that are more pest-resistant.

Methods used in IPM include the following:

IPM : It is an ecological pest-control strategy that uses a combination of biological, chemical, and physical methods together or in succession and requires an understanding of the ecology and life cycle of pests.

The primary cause of gas emissions from CAFOs is the decomposition of animal manure being stored in large quantities.

CAFOs release several types of gas emissions&#; ammonia, hydrogen sulfide, methane, and particulate matter.

Water pollution from CAFOs can affect both sources if one or the other is contaminated.

The two main contributors to water pollution caused by CAFOs are

States with high concentrations of CAFOs experience on average 20 to 30 serious water-quality problems per year as a result of manure management issues.

The large amounts of animal waste from CAFOs present a risk to water quality and aquatic ecosystems.

CAFO : It is an intensive animal feeding operation in which large numbers of animals are confined in feeding pens for over 45 days a year.

For aquaculture to be profitable, the species must be marketable, inexpensive to raise, efficient at converting feed into fish biomass, and disease resistant.

Aquaculture : Mariculture or fish farming. It includes the commercial growing of aquatic organisms for food and involves stocking, feeding, protecting from predators, and harvesting.

Aquatic plants require sunlight and are therefore largely restricted to shallow coastal waters, which make up less than 10% of the world&#;s ocean area yet contain 90% of all marine species.

Marine life, including fisheries, as well as terrestrial life, depends upon primary producers.

Fishing is an important industry that is under pressure from growing demand and falling supply.

Require fishing licenses and open inspections, which limit the number and kind of fish caught per year, and trade sanctions should these limits be exceeded.

Require and enforce labeling of fish products that were raised or caught according to sustainable methods.

Prevent the importation of fish products from countries that do not adhere to sustainable fishing practices.

Later, the pillars are removed and the mine collapses.

Room and pillar : Approximately half of the coal is left in place as pillars to support the roof of the active mining area.

Longwall : Uses a rotating drum with &#;teeth,&#; which is pulled back and forth across a coal seam&#;the material then breaks loose and is transported to the surface

Blast : Uses explosives to break up the seam, after which the material is loaded onto conveyors and transported to a processing center

Strip mining : Exposes coal by removing the soil above each coal seam

Open pit : Extracting rock or minerals from the Earth by their removal from an open pit when deposits of commercially useful ore or rocks are found near the surface

Mountaintop removal : Removal of mountaintops to expose coal seams and disposing of associated mining overburden in adjacent &#;valley fills&#;

In situ : Small holes are drilled into the Earth and toxic chemical solvents are injected to extract the resource.

Small dredges use suction or scoops to bring the mined material up from the bottom of a body of water.

Dredging : A method for mining below the water table and usually associated with gold mining.

Contour mining : Removing overburden from the seam in a pattern following the contours along a ridge or around a hillside.

Dust released during the breakup of materials, causing lung problems and posing other health risks

Disruption of soil microorganisms and, consequently, nutrient cycling processes

Chemicals from in situ leaching entering the water table

Areas that are experiencing the greatest growth in urbanization are countries in Asia and Africa.

Urbanization : It refers to the movement of people from rural areas to cities and the changes that accompany it.

Higher population densities increase crime rates. Population increase may be higher than job growth.

Urban areas attract industry due to the availability of raw materials, distribution networks, customers, and labor pool.

Solid-waste buildup is more pronounced. Landfill space becomes scarce and costly.

Since population densities are high, pollution levels are also high

Much of the pollution comes from point sources, enabling focused remediation techniques.

Commuting times are longer because the infrastructure cannot keep with growth.

Sanitation systems have greater volumes of wastes to deal with.

Single-use development : Separate commercial, residential, institutional, and industrial areas. Thus, people live, work, shop, and play far apart and need a car.

Most housing is single-family homes on large lots with fewer stories than city homes, farther apart, and separated by lawns, landscaping, or roads.

Agricultural lands , which are/were frequently found immediately surrounding cities, are frequently taken from for urban sprawl.

Job sprawl : It has low-density, geographically spread-out employment patterns, with most jobs in a metropolitan area outside the central business district and increasingly in the suburbs.

Urban Sprawl : Also known as suburban, describes the expansion of human populations away from central urban areas into low-density and usually car-dependent communities.

Providing property tax incentives to companies that locate in urban centers

Creating greenbelts and another undeveloped, wild, or agricultural land around cities

Smart growth : It promotes compact, transit-oriented, walkable, bicycle-friendly land use, neighborhood schools, and mixed-use development with a variety of housing options to slow urban sprawl and concentrate growth in a compact, walkable "urban villages."

Conserving water through the use of xeriscaping

Preserving community history and culture while blending into its natural aesthetics

Locating buildings near multi-modal public transportation hubs like light rail, subways, and park and rides.

Conserving energy through government and private industry rebates and tax incentives for solar and other clean energy

Some urban development strategies include the following:

Urban development : It is the process of designing and shaping the physical features of cities and towns with the goal of making urban areas more attractive, functional, and sustainable.

Frequently using street-sweeping vacuums that can reduce the trash and other debris and pollutants that end up in runoff

Water retention-infiltration basins&#;shallow artificial ponds&#;infiltrate storm water into the groundwater aquifer through permeable soils.

Constructing wetlands to naturally filter water before it enters lakes, rivers, and oceans.

As urban heat transfers to streams and waterways, fish and wildlife suffer.

Erosion causes runoff sedimentation, which settles to the bottom of water bodies and reservoirs, affecting water quality and storage capacity.

Urban runoff results in the following:

This runoff is a major source of urban flooding and water pollution in urban communities worldwide.

Urban runoff : It is surface runoff of rainwater created by urbanization.

It represent the amount of biologically productive land and sea area that is necessary to supply the resources a human population consumes, and to assimilate associated waste.

Ecological Footprint : A measure of human demand on Earth&#;s ecosystems and is a standardized measure of demand for natural capital that may be contrasted with the planet&#;s ecological capacity to regenerate.

Sustainable agricultural practices, reducing consumption and waste, universal fishing quotas, and collaborative water management is needed to solve environmental issues caused by unsustainable resource use and pollution.

To ensure that available resources are never depleted faster than those resources can be replaced.

Sustainability : It refers to the capacity for the biosphere and human civilization to coexist through the balance of resources within their environment.

Using cover crops, green manure, and animal manure to build soil quality and fertility

Reducing or eliminating tillage in a manner that is consistent with effective weed control

Examples of sustainable agricultural practices include the following:

It prioritizes long-term solutions over short-term symptoms and land and rural community health.

Sustainable agriculture : It emphasizes profitable, environmentally friendly, energy-efficient production and food systems that improve farmers' and the public's quality of life.

Windbreaks : Rows of trees that provide shelter or protection from the wind

Terracing : Make or form (sloping land) into a number of level flat areas resembling a series of steps

Strip cropping : Cultivation in which different crops are sown in alternate strips

No-till agriculture : Soil is left undisturbed by tillage and the residue is left on the soil surface.

Contour plowing : Plowing along the contours of the land in order to minimize soil erosion

Human civilization requires energy to function. Humans obtain energy from resources such as fossil fuels, nuclear fuel, or renewable energy.

It is heated to high temperatures by the conversion of nuclear energy to heat in its core by the process of nuclear fusion.

Sun : The source of energy for most of life on Earth.

Energy : Defined as the fundamental entity of nature that is transferred between parts of a system in the production of physical change within the system and is usually regarded as the capacity for doing work.

Thermal Energy : the energy an object has because of the movement of its molecules.

Nuclear energy : It is stored in the nuclei of atoms, and it is released by either splitting or joining atoms.

Electrical energy : It results from the motion of electrons.

Chemical energy : It is stored in bonds between atoms in a molecule.

A billing unit of energy delivered to consumers by electric utilities.

Kilowatt hour (kWh ): A unit of power; a measure of energy used at a give moment.

British thermal unit (Btu): It is the amount of heat required to raise the temperature of 1 pound of water by 1°F.

Zeroth Law of Thermodynamics : If a body A is in thermal equilibrium with another body B, and body A is also in thermal equilibrium with a body C, then this implies that the bodies B and C are also in equilibrium with each other.

Second Law of Thermodynamics : The total system work is always less than the heat supplied into the system.

First Law of Thermodynamics : The law of conservation of energy; energy can't be created nor destroyed.

Technology already exists for their use.

Infrastructure already in place for extraction, processing, and delivery

Abundant supply, resulting in relatively low prices for consumers

Arguments used to defend the continued use of fossil fuels include the following:

Nonrenewable Energy Sources: Their use is not sustainable because their formation takes billions of years like fossil fuels.

Renewable energy resources exist over wide geographical areas, in contrast to other energy sources that are concentrated in a limited number of countries.

Renewable energy : Defined as energy that is collected from resources that are naturally replenished on a human time scale.

Cogeneration : Also known as combined heat and power (CHP), is an efficient technology to generate electricity and heat simultaneously at local facilities; otherwise, the heat produced from electricity generation is wasted.

Oil : A fossil fuel produced by the decomposition of deeply buried organic material (plants) under high temperatures and pressure for millions of years.

Natural gas : A fossil fuel formed when layers of buried plants and gases are exposed to intense heat and pressure over thousands of years.

Clean Coal : Technology that attempts to mitigate emissions of carbon dioxide and other greenhouse gases that arise from the burning of coal for electrical power.

Anthracite : Used primarily for residential and commercial space heating.

Bituminous : Used primarily as fuel in steam-electric power generation.

Lignite : Often called brown coal, is the type most harmful to human health and is used almost exclusively as the primary fuel for electric power generation around the world.

Coal : Formed when dead plant matter that covered much of Earth&#;s tropical land surface at one time decays into peat and is then converted into coal by the heat and pressure of deep burial over millions of years.

Peat : It is an accumulation of partially decayed vegetation or organic matter, mostly wetland vegetation like mosses, sedges, and shrubs, that forms in acidic and anaerobic conditions.

Burning wood fuel : It creates the following by-products: carbon dioxide, heat, steam, water vapor, and wood ash.

Technologies used to remove pollutants from flue gases

Sorbents : Activated charcoal, calcium compounds, or silicates can convert gaseous pollutants in smokestacks into compounds that baghouse filters, electrostatic precipitation, or scrubbers can collect.

It can also be used to reduce SOx and particulates from burning coal.

Scrubbers : Systems that inject chemical(s) into a dirty exhaust stream to &#;wash out&#; acidic gases.

This process can be used to reduce the amount of NOx, SOx, and particulates.

Fluidized-bed combustion : A method of burning coal in which the amount of air required for combustion far exceeds that found in conventional burners.

Electrostatic precipitator : A filtration device that removes fine particles, like dust and smoke, from a flowing gas using an electrostatic charge.

Cyclone separator : A method of removing particulates through rotational (spinning) effects and gravity.

Impurities are removed from the syngas before it is combusted, which results in lower emissions of sulfur dioxide, particulates, and mercury.

Coal gasification : A process that turns coal and other carbon-based fuels into gas known as &#;syngas.&#;

Burning pulverized coal at lower temperatures : Coal is crushed into a very fine powder and injected into a firebox.

Baghouse filters : Fabric filters that can be used to reduce particulates.

Oil is a liquid fossil fuel that formed from the remains of marine organisms, these deposits became trapped in small spaces in rock and sediment , which now can be accessed by drilling.

Natural gas was formed from the remains of marine organisms and is relatively abundant and clean when compared to coal and oil.

Coal originally comes from land vegetation , which over millions of years decays and becomes compacted.

Fossil fuels are formed over time from deposits of once-living organisms and take thousands of years to form.

Law of Demand : All other factors being equal, the quantity of the item purchased is inversely related to the price of the item.

As the price of an item goes up, suppliers will attempt to maximize their profits by increasing the quantity offered for sale.

Law of Supply : All other factors being equal, as the price of a good or service increases, the quantity of goods or services that suppliers offer will increase, and vice versa.

Tar sands : Contain bitumen&#;a semi-solid form of oil that does not flow. These are mined using strip mining techniques; in situ methods, using steam, can also be used to extract bitumen from tar sands.

Synfuels : Any fuel produced from coal, natural gas, or biomass through chemical conversion.

Oil shale : An organic-rich, fine-grained sedimentary rock containing a solid mixture of organic chemical compounds (kerogen) from which liquid hydrocarbons (shale oil) can be produced.

Methane Hydrates (Clathrates) : These are recently discovered source of methane that form at low temperature and high pressure.

The combustion of any fossil fuel follows the following reaction:

Carbon dioxide produced during fossil fuel combustion for heat and electricity generation is a major contributor to global CO2 emissions considered responsible for global warming due to its greenhouse gas effect.

Using a rotary generator to convert the turbine&#;s mechanical energy into electrical energy.

Converting the thermal energy of the steam into kinetic energy in the turbine; and

Extracting thermal energy from the fuel and using it to raise steam;

It is commonly used in low-permeability rocks like sandstone, shale, and some coal beds to increase oil and/or gas flow to a well from petroleum-bearing rock formations.

This process is intended to create new fractures in the rock as well as increase the size, extent, and connectivity of existing fractures.

Hydraulic fracturing : Also known as &#;fracking,&#; is an oil and gas well development process that typically involves injecting water, sand, and chemicals under high pressure into a bedrock formation via a well.

Nuclear Meltdown : A severe nuclear reactor accident that results in core damage from overheating.

If the reaction is not controlled, a &#;meltdown&#; can result.

If controlled, the heat that is produced is used to produce steam that turns generators that then produce electricity.

The reaction gives off heat.

During nuclear fission , an atom splits into two or smaller nuclei along with by-product particles.

Its fission provides about one-third of the total energy produced in a typical commercial nuclear power plant.

Pu-239 : It has a half-life of 24,000 years and is produced in breeder reactors from U-238.

When hit by neutron, it eventually decays into Pu-239.

U-238 : The most common isotope of uranium and has a half-life of 4.5 billion years.

Critical Mass: The minimum amount of U-235 required for a chain reaction.

U-235 : Less than 1% of all-natural uranium on Earth.

Moderator : It reduces the speed of fast neutrons, thereby allowing a sustainable chain reaction.

Control rods : Move in and out of the core to absorb neutrons and slow down the reaction.

The fission of an atom of uranium produces 10 million times the energy produced by the combustion of an atom of carbon from coal.

Fuel : Enriched (concentrated) U-235 is usually the fuel.

Each fuel rod is stacked with many fuel pellets.

Core : Contains up to 50,000 fuel rods.

It can be produced anywhere as opposed to fossil fuels.

These are biodegradable, can be converted into biodiesel or bioethanol to power vehicles.

Reduces the methane emissions from landfills that contribute to global warming.

Reduces the impact of land disturbances required for coal mining.

Reduces the reliance on coal and oil.

Anaerobic digestion : A collection of processes by which microorganisms break down biodegradable material, in the absence of oxygen, to produce methane gas, which is then burned to produce energy.

It can be grown on marginal land that is not suitable for agriculture.

Biomass: It is biological material derived from living, or recently living, organisms that can be burned in large incinerators to create steam that is used for generating electricity.

Residential photovoltaic system : It consists of solar panels to absorb and convert sunlight into electricity, a solar inverter to change the electric current from DC to AC, and a battery storage and backup system.

Active solar heating : It generates more heat than passive systems, and relies on three components: a solar collector to absorb the solar energy, a solar storage system, and a heat transfer system.

Passive solar heating : It does not include any type of mechanical heating device and functions by incorporating building features that absorb heat and then release it slowly to maintain the temperature throughout the building.

Electrical power and heat is generated at home and at industrial sites through photovoltaic cells, solar collectors, or at a central solar-thermal plant.

Solar energy : It consists of collecting and harnessing radiant energy from the sun to provide heat and/or electricity.

Natural hazards, such as wildfires, reduce the supply of vegetation that absorbs rainfall

Floods can be caused by the following:

Dams reduce the amount of land available for agriculture.

Dams destroy wildlife habitats and keep fish from migrating.

Dams create large flooded areas behind the dam from which people are displaced.

Provide water storage for municipal and agricultural use

Low operating and maintenance costs, which result in affordable electricity

There are about 75,000 dams in the United States that block ~600,000 miles (~1 million km) of what had once been free-flowing rivers.

Hydroelectric generation accounts for approximately 44% of renewable electricity generation, and 6.5% of total electricity generation in the United States.

Dams : These are built to trap water, which is then released and channeled through turbines that generate electricity.

Heat contained in underground rock and fluids from molten rock (magma), hot dry-rock zones, and warm-rock reservoirs produces pockets of underground steam and hot water that can be used to drive turbines, which can then generate electricity.

The hydrogen ions then move through a membrane, where they combine with oxygen and electrons to produce water.

The electrons flow out of the cell to be used as electrical energy.

The hydrogen reacts with a catalyst to form negatively charged electrons and positively charged hydrogen ions (H+).

The hydrogen fuel cell operates similarly to a battery with two electrodes&#;oxygen passes over one and hydrogen passes over the other.

There has been a 25% increase in wind turbine use in the last decade, but wind energy only provides a small percentage of the world&#;s energy.

The country with the largest wind energy installed capacity is China, followed by the United States.

The largest turbines can harness energy to power 600 American homes.

The current capacity of wind power in the United States powers approximately 20 million homes.

About 6% of the electrical demand in the United States is now produced from wind energy.

One megawatt of wind energy can offset approximately 2,600 tons of CO2.

Using wind power is by far the most efficient method of producing electricity

Wind turns the giant turbine blades, and then that motion powers generators.

Wind turbines work very simply: instead of using electricity to make wind&#;like a fan&#;wind turbines use wind to make electricity.

75% of the electricity used to power home electronics is consumed while the products are turned off.

Phantom Load : Refers to the energy that an appliance or an electronic device consumes when it is not actually turned on.

LED lights do not contain mercury and can be disposed of with the regular household trash.

A programmable thermostat can save as much as 15% on heating and cooling costs.

Improving attic insulation and sealing air leaks can save 10% or more on annual energy bills.

Criteria air pollutants : These are a set of eight air pollutants that cause smog, acid rain, and other health hazards and are typically emitted from many sources in the industry, mining, transportation, power generation, and agriculture.

Non-point source air pollution : It occurs when the contaminant comes from a source that is not easily identifiable or from a number of sources spread over a large, widespread area.

Point source air pollution : It occurs when the contaminant comes from an obvious source.

Secondary Pollutants : Result from primary air pollutants&#; reacting together and forming new pollutants.

Parts per million (ppm) : The most common form of expressing air pollutants.

Air pollution : It occurs when harmful or excessive quantities of substances are introduced into Earth&#;s atmosphere.

Sulfur trioxide reacts with water vapor in the air to form sulfuric acid.

Sulfur in oil and coal reacts with oxygen gas to produce sulfur dioxide.

Unburned carbon ends up as soot or particulate matter (PM).

Carbon in coal or oil is burned in oxygen gas to produce carbon dioxide and carbon monoxide gas.

Industrial smog : Trends to be sulfur-based and is also called gray smog.

Requiring catalytic converters on all cars worldwide; however, this only converts carbon monoxide to carbon dioxide&#;a greenhouse gas

Methods to reduce carbon monoxide pollution include the following:

Carbon monoxide is present in small amounts in the atmosphere, primarily as a product of the following:

It forms when there is not enough oxygen to produce carbon dioxide.

Carbon monoxide : It is a colorless, odorless, and tasteless gas that is slightly less dense than air and is produced from the partial oxidation of carbon-containing compounds.

Symptoms of lead poisoning include failure of the blood to make hemoglobin, which results in anemia disruptors, mental retardation and disabilities, hypertension, miscarriages and/or premature births, and even death at relatively low concentrations.

Exposure to lead can occur from inhalation of polluted air and dust and from the ingestion of lead in food and/or water.

Lead : It is used in building construction, lead-acid batteries for vehicles, bullets and shot fishing weights, solder, and shields for radiation.

It is formed by denitrification and nitrification.

Nitrous oxide : It is a major air pollutant, with levels of N2O having increased by more than 15% since .

These gases are formed whenever nitrogen occurs in the presence of high-temperature combustion.

Nitrogen Oxide : A generic term for nitric oxide and nitrogen dioxide, which are produced from the reaction of nitrogen and oxygen gases in the air.

Result in heart attacks and other cardiopulmonary problems

Tropospheric ozone can have the following effects:

Tropospheric ozone : It does not have strong global effects, but instead is more influential in its effects on smaller, more localized areas.

Ozone : It is an inorganic molecule with the chemical formula O3, and tropospheric (ground-level) ozone is a secondary air pollutant.

Reducing the reliance on fossil fuels, especially oil and coal

Reducing the incineration of municipal and industrial wastes

Limiting wood-burning fireplaces and stoves in new home construction

Methods to reduce PANs include the following:

Peroxyacyl Nitrates (PANs) : These are secondary pollutants. Because they break apart quite slowly in the atmosphere into radicals nd NO2, PANs are able to move far away from their urban and industrial origin.

Using scrubbers in the smokestacks

Steps that can be taken to reduce the amount of SO2 in the atmosphere include the following:

It irritates the throat and lungs, and, if there are fine dust particles in the air, can damage the respiratory system.

Sulfur dioxide, emitted in sufficient quantities at low or ground level, can combine with air moisture to form an acid solution that dissolves stonework.

It is toxic to a variety of plants and reduces crop yields.

Sulfur dioxide emissions come from power stations, oil refineries, and large industrial plants burning fossil fuels.

Sulfuric Dioxide: A colorless gas with a penetrating, choking odor that readily dissolves in water to form an acidic solution.

not using wood in fireplaces

not burning leaves and other yard waste;

limiting the use of household and personal products that cause fumes;

increasing air-quality standards for emissions of particulate matter from smokestacks;

Airborne particulate matter can be reduced by:

depletes the nutrients in the soil;

changes the nutrient balance in coastal waters and large river basins;

Larger particles tend to settle to the ground by gravity in a matter of hours, whereas the smallest particles can stay in the atmosphere for weeks and are mostly removed by precipitation.

The smaller and lighter a particle is, the longer it will stay in the air.

The &#;x&#; refers to the size of the particle.

Suspended particulate matter (PMx) : It is microscopic solid or liquid matter suspended in Earth&#;s atmosphere.

damage to the liver, kidney, and central nervous system;

Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate and enter the surrounding air.

Volcanic Organic Compounds (VOCs ): These are organic chemicals that have a high vapor pressure (easily evaporate) at ordinary room temperature.

4 P.M.&#;Sunset: As the sun goes down, the production of ozone is halted.

Nitrogen dioxide can also react with VOCs released by vehicles, refineries, and gas stations to produce toxic PANs (peroxyacyl nitrates).

Nitrogen dioxide also reacts with water vapor to produce nitric acid (HNO3) and nitric oxide (NO).

11 P.M.&#;4 P.M.: As the sunlight becomes more intense, nitrogen dioxide is broken down and the concentration of ozone (O3) increases.

9 A.M.&#;11 A.M.: As traffic begins to decrease, nitrogen oxides and VOCs begin to react, forming nitrogen dioxide (NO2).

6 A.M.&#;9 A.M.: As people drive to work, concentrations of nitrogen oxides and VOCs increase.

Photochemical smog : It is catalyzed by ultraviolet (UV) radiation, tends to be nitrogen-based, and is referred to as brown smog.

A warm air mass moving over a colder one traps the cooler air below and stills the air, trapping dust and pollutants and increasing their concentrations.

This usually happens at night when solar heating stops and the surface cools, cooling the atmosphere above it.

This effect traps pollution like smog close to the ground, which may harm human health.

Thermal inversions : These occur when air temperature rises with height instead of falling.

Cigarette smoke : It contains almost 5,000 chemical compounds, including 60 known carcinogens (cancer-causing chemicals), one of which is dioxin.

Radon : It is an invisible radioactive gas that results from the radioactive decay of radium, which can be found in rock formations beneath buildings.

Formaldehyde : It is an organic chemical that is prevalent in the indoor environment and is a carcinogen that is linked to lung cancer.

Carbon monoxide poisoning : It is the most common type of fatal indoor air poisoning in many countries because it easily combines with hemoglobin to block the blood&#;s oxygen-carrying capacity.

Asbestos : It is inexpensive, durable, and flexible and naturally acts as an insulating and fireproofing agent.

&#;Sick building&#; syndrome (SBS) : It is a term used to describe a combination of ailments associated with an individual&#;s place of work or residence.

Test for radon gas and other dangerous indoor pollutants.

Do not allow smoking indoors.

Most present-day vehicles that run on gasoline are fitted with a &#;three way&#; converter, since it converts the three main pollutants:

Catalyst : It stimulates a chemical reaction in which by-products of combustion are converted to less toxic substances by way of catalyzed chemical reactions.

Catalytic converter : It is an exhaust emission control device that converts toxic chemicals in the exhaust of an internal-combustion engine into less harmful substances.

Oxidation of unburned hydrocarbons to carbon dioxide and water:

Catalytic converters remove hydrocarbons and other harmful emissions, but they do not reduce fossil fuel-produced carbon dioxide.

Reduction of nitrogen oxides to nitrogen and oxygen:

When buying a car, consider its fuel efficiency.

Use fans instead of air conditioners.

Use mass transit systems or carpool when possible.

Reduce idling and turn off engines while waiting.

Maintain vehicle properly with regular tune-ups and oil changes.

Drive within the speed limit and keep tires inflated.

Distribute solar cook stoves to developing countries to replace wood and coal.

They are also found in volcanic vent gases and are formed by forest fires, bacterial action in the soil, and lightning-induced atmospheric reactions.

Acid deposition due to nitrogen oxides begins with nitrogen oxides formed by burning oil, coal, or natural gas.

It then combines with water vapor to form sulfurous acid which then reacts with oxygen to form sulfuric acid.

Acid deposition due to sulfur dioxide begins with sulfur dioxide being introduced into the atmosphere by burning coal and oil, smelting metals, organic decay, and ocean spray.

Acid shock : Caused by rapid melting of snow pack with dry acidic particles, raises lake and stream acid concentrations five to ten times higher than acidic rainfall.

It damages trees at high elevations and many sensitive forest soils by nitrogen saturation and acidification that harms decomposers and mycorrhizal fungi.

Acid rain : It causes acidification of lakes and streams.

Wet Deposition : Acid rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals.

Dry Deposition : In dry areas, acidic chemicals in the air may become dust or smoke and stick to the ground, buildings, homes, cars, and trees, which rainstorms wash away, increasing acidic runoff.

Acid deposition : It occurs when atmospheric chemical processes transform sulfur and nitrogen compounds and other substances into wet or dry deposits on Earth.

Vegetation changes due to soil pH and ecosystem changes affect food webs.

Changes in animal life due to changes in vegetation

Urban heat islands can directly influence the health and welfare of urban residents who cannot afford air conditioning

High levels of pollution in urban areas can also create a localized greenhouse effect.

Street Canyon : A place where the street is flanked by buildings on both sides, creating a canyon-like environment.

More black asphalt and building surfaces absorb heat and reduce sunlight reflectivity.

There is a lack of vegetation and standing water.

Urban impervious materials reduce the cooling effect of soil and leaf evaporation and tree shading.

Reasons for higher urban temperatures are as follows:

Since warmer air can hold more water vapor, rainfall can be as much as 30% greater downwind of cities when compared with areas upwind.

Urban heat islands : These occur in metropolitan areas that are significantly warmer than their surroundings.

The dominant form of noise pollution is from transportation sources.

Noise pollution : It is an unwanted human-created sound that disrupts the environment.

cardiovascular problems, which manifest as an accelerated heartbeat and high blood pressure; and

a decrease in alertness and the ability to memorize;

Sensory hearing loss is caused by damage to the inner ear and is the most common form associated with noise pollution.

Create computer-controlled traffic flow devices that reduce braking and acceleration, and implement changes in tire designs.

Control residential noise, such as power tools, garden equipment, and loud entertainment equipment, through local laws and enforcement.

Thermal Pollution : The degradation of water quality by any process that changes ambient water temperature.

Non-point source pollution : A combination of pollutants from a large area rather than from specific identifiable sources

Point source pollution : Release pollutants from known locations, such as discharge pipes, that are regulated by federal and state agencies.

This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.

Water pollution : It is the contamination of water bodies.

Using monetary and tax incentives to convert existing watering systems to drip irrigation and to replace landscaping with native vegetation that is less water-demanding

Upgrading existing water treatment plants to better control nitrate and phosphate pollution through tertiary standards and other advanced technologies

Updating building codes to utilize permeable pavement to absorb the excess urban runoff

Planting vegetation (buffer zones) along streambeds, which slows erosion and absorbs some of the excess nutrients

Controlling the application and timing of applying fertilizer

Use of household products that contain phosphates

Sewer and drainage overflows can occur when the rainfall amount exceeds the wastewater treatment capacity

Fertilizers and pesticides from residential and agricultural runoff

Discharge from water treatment facilities that do not have the capacity to handle nutrient and biodegradable waste discharge

Changes in species composition and dominance

Cultural eutrophication : It is the process whereby human activity increases the amount of nutrients entering surface waters.

Disease-causing microorganisms : Such as bacteria, viruses, and protozoa, can result in swimmers getting sick and shellfish becoming contaminated.

Phosphates : These are also a component of fertilizers; however, they are not water-soluble, and they adhere to soil particles.

Nitrates : These are water-soluble and are found in fertilizers, which can remain on fields and accumulate, leach into groundwater, or end up in surface runoff and cause algal blooms in surface waters, resulting in decreased dissolved oxygen levels.

Mining companies in developing nations dump waste into rivers and other waterways.

Cyanide is intentionally poured onto piles of mined rock to chemically extract gold.

The use of microorganisms to break down the oil.

Controlled burning, booming, skimming, and/or vacuuming oil from the surface or shoreline.

Dispersants, sorbents, and detergents disperse, absorb, or clump oil into sinking gel-like agglomerations.

Oil penetrates seabird feathers, making them less buoyant and more susceptible to temperature changes.

Oil floats on water, blocking sunlight from reaching marine plants and phytoplankton, affecting the ecosystem's food web.

Due to their limited foraging, they dehydrate quickly.

Seabirds ingest their feather oil while preening, damaging their kidneys and livers.

As the plastic further disintegrates , it becomes small enough to be ingested by aquatic organisms and birds near the ocean&#;s surface and eventually enters the marine food chain.

As the plastic photodegrades into smaller and smaller pieces, it remains as plastic polymers leaching toxic chemicals into the upper water column.

As materials are captured in the currents, the wind-driven surface currents gradually move floating debris toward and trap it in the center of the gyre.

Great Patch : Formed as a result of marine pollution gathered by oceanic currents as the gyre&#;s rotational pattern drew in waste material from across the North Pacific Ocean.

Great Pacific Garbage Patch : A large system of rotating ocean currents of marine litter in the central North Pacific Ocean and is characterized by high concentrations of floating plastics, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre.

reduce biodiversity and seriously impact food webs in the area since there is less vegetation available for primary consumers.

increase groundwater depletion as water does not infiltrate into the soil to recharge aquifers; and

create microclimates due to the high heat capacity of asphalt

Urban Runoffs are the major source of urban flooding and water pollution in urban communities worldwide. It also creates:

High-fat solubility, which makes them able to pass through biological membranes and bioaccumulate in the fatty tissues of living organisms

A tendency to evaporate easily in hot regions and accumulate in cold regions, where they tend to condense and persist

Ability to travel long distances through the atmosphere before being deposited on Earth.

Chemical characteristics of POPs include the following:

It has been observed to persist in the environment, be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and have potentially significant impacts on human health and the environment.

Persistent Organic Pollutants : These are organic (carbon) compounds that are resistant to environmental degradation through chemical or biological processes or decomposition due to light.

Water testing : It is a broad description for various procedures that are used to analyze water quality.

Water quality : Refers to the chemical, physical, and biological characteristics of water and is a measure of the condition of the water relative to the requirements of one or more biotic species and/or to any human need or purpose.

Turbidity : It is a measure of how light is scattered in the water column due to solids that do not dissolve but are small enough to be suspended in the water.

Increased concentrations of these ions can increase the solubility of heavy metal ions in water and affect the water&#;s buffering capacity.

Total hardness : It measures the total concentration of calcium and magnesium ions in the water.

Higher temperatures also increase an organism&#;s sensitivity to toxic wastes and diseases.

gases are less soluble in warmer water; and

High levels of total dissolved solids (TDS) can affect water clarity and photosynthesis and lead to a decline in the quality and taste of drinking water.

A steady concentration of dissolved minerals is necessary to maintain the osmotic balance within the cells of organisms.

Decreased salinity also results in decreased DO and decreased viability of eggs and larvae.

Proper salinity levels are required to maintain osmotic pressure for living cells.

Excessive amounts of phosphorus build up easily, and small amounts can contaminate large volumes of water.

Phosphates : These are essential nutrients for aquatic plants, but only in very low concentrations.

Fresh rainwater may have a pH of 5.5 to 6.0 due to carbon dioxide dissolving in the water, making a weak carbonic acid solution.

Most bodies of water have the highest biological diversity when the pH is near 7, with natural waters having pH values from 5.0 to 8.5.

Pollution tends to make water acidic and increases the solubility of heavy metals.

Changes in water pH can result in increased mortality of eggs and juveniles, decalcification of bone, and physiological stress.

Nitrite : Occurs in water as an intermediate product in the biological breakdown of organic nitrogen being produced either through the oxidation of ammonia or the reduction of nitrate.

Nitrate : This gets reduced to nitrites, which can be harmful to humans and fish.

Heavy metals are non-biodegradable and can cause decreased reproductive rates and birth defects.

Metals can become &#;locked up&#; in bottom sediments, where they remain for many years.

As water becomes more acidic, metal solubility increases, and the metal particles become more mobile.

Fecal coliforms : They can get into the water from untreated human sewage or from farms and runoff from animal feedlots.

Coliforms : These are a form of bacteria that are found in the intestines of warm-blooded animals; their presence in lakes, streams, and rivers is a sign of untreated sewage in the water.

Dissolved Oxygen (DO) : If its level is too low, it indicates possible water pollution and shows a potential for further pollution downstream because the ability of the stream to self-cleanse will be reduced.

Low CO2 levels also result in a decreased rate of photosynthesis.

High CO2 levels also make it difficult for fish to use the limited amount of oxygen present in the water and to discharge the CO2 in their bloodstream.

When the oxygen concentration falls the carbon dioxide concentration increases and the pH increases.

Carbon Dioxide : Aquatic vegetation, ranging from phytoplankton to large rooted plants, depends upon carbon dioxide and bicarbonates in the water for growth.

Biological Oxygen Demand (BOD) : It gives an approximation of the level of biodegradable waste in water.

It is rapidly oxidized by certain bacteria in natural water systems into nitrite and nitrate.

Ammonia : When found in natural water, is regarded as an indicator of pollution.

The water source's ability to resist pH changes can increase fish egg, larva, and fry survival rates.

Alkalinity : It measures the sum of the bicarbonate, carbonate, and hydroxide ions in the water, which raise the pH.

Ion exchange : Removes inorganic constituents and can be used to remove arsenic, chromium, excess fluoride, nitrates, radium, and uranium

Flocculation sedimentation : A process that combines small particles into larger particles that then settle out of the water as sediment

It clarifies water and enhances the effectiveness of disinfection.

Filtration : Removes clays, natural organic matter, precipitants, and silts from the treatment process.

Disinfection : Using chemicals and/or cleansing techniques that destroy or prevent the growth of organisms that are capable of infection.

Adsorption : When one substance just hangs onto the outside of another.

Absorption : When one substance enters completely into another.

Polychlorinated biphenyls (PCBs) : Used to make electrical equipment, heat transfer fluids and lubricants.

Phthalates : Used to make plastics more flexible.

Dioxins : By-product of herbicide production and paper bleaching, and released during burning wastes and wildfires.

Bisphenol A (BPA) : Used in plastic manufacturing and epoxy.

Endocrine disruptors : These are chemicals that can interfere with endocrine or hormonal systems and can cause behavior, learning and developmental disorders, birth defects, cancerous tumors, and loss of fertility.

Endocrine System : A network of glands that make the hormones that help cells communicate with each other and is responsible for almost every cell, organ, and function in both humans and animals.

Gland : An organ that secretes particular chemical substances for use in the body or for discharge into the surroundings.

An increase in hurricanes resulted in more frequent sea surges.

Filling in these sensitive areas for urban development impacts water quality and runoff; and

Since the Industrial Revolution, humans have had an increasingly negative impact on one of the most productive ecosystems on Earth through:

They have a complex salt filtration system and root system to survive salt water, low-oxygen mud, and wave action.

Mangrove : A shrub or small tree that grows in slightly salty (brackish) water formed by seawater mixing with freshwater in estuaries.

Wetlands also allow for the cultivation of rice, a food source for half of the world&#;s population.

Wetlands support high animal concentrations and serve as breeding grounds and nurseries for many species, making their destruction a major environmental issue.

It includes marshes, ponds, the edge of a lake or ocean, the delta at the mouth of a river, and low-lying areas that frequently flood.

Wetland : It is a place where the land is covered by water, which can be freshwater, saltwater, or brackish water.

The pollutant must be biologically active.

The pollutant must be soluble in fats.

The pollutant must be mobile.

The pollutant must be long-lived.

For biomagnification to occur, the following must be true:

Biomagnification : It is the increasing concentration of a substance in the tissues of organisms at successively higher trophic levels within a food chain.

The lipid (fat) content of the organism

The transformation of the substance by metabolic processes

The rate at which the substance is eliminated from the organism

The degree of fat solubility of the pollutant

The rate at which a given substance bioaccumulates depends upon the following:

Bioaccumulation : It is the increase in the concentration of a pollutant within an organism.

Cotton and cloth can take two to five months to decompose.

Some plastics can take up to 1 million years to decompose.

Paper decomposes in 10 to 30 days, while glass does not decompose.

These can take hundreds of thousands of years to decompose.

Wood can take 10 to 15 years to decompose.

Usually decompose within two weeks.

These wastes can take hundreds of years to decompose.

Municipal solid waste (MSW) : More commonly known as trash or garbage&#;consists of everyday items that are used and then thrown away.

Nutrient-rich digestate can be used as fertilizer.

It is best suited for organic material and is commonly used for industrial effluent, wastewater, and sewage sludge treatment.

It reduces the methane emission from landfills.

It reduces or eliminates the energy footprint of waste treatment plants.

It reduces the amount of organic matter, which might otherwise be destined to be dumped at sea or in landfills or burned in incinerators.

Microorganisms: Are used to break down biodegradable material and sewage sludge in the absence of oxygen.

Puron® : Substitutes fluorine for chlorine, and has less of an impact on the stratospheric ozone layer.

Freon® : Its molecular structure contains chlorine, which seriously degrades the stratospheric ozone layer.

Reducing : Lessening the number of hazardous wastes by substituting and using products that are more &#;Earth-friendly.&#;

Sanitary landfills : Method of waste disposal where the waste is buried either underground or in large piles, and where waste is isolated from the environment until it is safe.

Ocean dumping : The deliberate disposal of municipal and/or hazardous wastes at sea.

Toxic or hazardous wastes are often exported from developed countries to developing countries.

Global waste trade : It is the international trade of waste between countries for further treatment, disposal, and/or recycling.

Incineration : A waste treatment process that involves the combustion of substances contained in waste materials and the conversion of the waste into ash, flue gas, and heat.

When disposed, these toxins may leach and pollute the groundwater.

Toxic wastes : These are wastes that are harmful or fatal when ingested or absorbed.

Teratogens : These are substances found in the environment that can cause birth defects.

Source-specific wastes : These are wastes from specific industries.

Reactive wastes : These are wastes that are unstable under normal conditions. Reactive wastes can cause explosions, gases, toxic fumes, or vapors when heated, compressed, or mixed with water.

High-level radioactive wastes : Contain high levels of radiation and remain dangerous for a very long time

Low-level radioactive wastes : Contain low levels of radiation and remain dangerous for a relatively short time.

This waste is hazardous to most forms of life and the environment and is regulated by government agencies to protect human health and the environment.

Radioactive wastes : Usually a by-product of nuclear power generation and other applications of nuclear fission, such as research and medicine.

Permanent storage : Isolates hazardous waste from the environment by condensing or concentrating it.

Hazardous waste landfills : Excavated or engineered sites for the final disposal of non-liquid hazardous waste are selected and designed to minimize environmental release.

Landfill capping : A containment technology that forms a barrier between the contaminated media and the surface, protecting humans and the environment from its harmful effects and limiting its migration.

Methods Used to Isolate and Store Hazardous Wastes

Brownfield : It is land that was previously used for industrial or commercial purposes, may have been contaminated with hazardous wastes, and is commonly found in large urban areas.

Reduction and cleanup of hazardous wastes : These can occur by producing less waste, converting the hazardous material to less hazardous or nonhazardous substances, and placing the toxic material into perpetual storage.

Waste piles : These are non-containerized piles of solid, non-liquid hazardous waste that are used for temporary storage or treatment.

Injection wells : These stores fluid deep underground in geologically stable, porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer.

Surface impoundments : These are natural topographic depressions, man-made excavations, or diked areas that are used for temporary storage and/or for the treatment of liquid hazardous waste.

Salt dome and bed formations, underground caves, and mines are geologic repositories .

Halocarbons (halons) : These are organic chemical molecules that are composed of at least one carbon atom with one or more halogen atoms; the most common halogens are fluorine, chlorine, bromine, and iodine.

Chlorofluorocarbons : These are nonflammable chemicals that contain atoms of carbon, chlorine, and fluorine.

There are no natural reservoirs of chlorofluorocarbons (CFCs) or halocarbons (halons), but their chemical stability allows them to reach the stratosphere and degrade the ozone layer.

Ozone : A highly reactive molecule and is constantly being formed and broken down in the stratosphere.

Ozone Layer : A belt of naturally occurring ozone gas that sits between 9 and 19 miles (15&#;30 km) above Earth and serves as a shield from the harmful ultraviolet B radiation emitted by the sun.

UVC : It is found only in the stratosphere and is largely responsible for the formation of ozone.

UVB : It causes blistering sunburns and is associated with skin cancer.

UVA : It is closest to blue light in the visible spectrum and is the form of ultraviolet radiation that usually causes skin tanning.

Ultraviolet radiation is subdivided into three forms:

Atomic oxygen can combine with oxygen molecules to form ozone .

Stratosphere : Contains approximately 97% of the ozone in the atmosphere, and most of it lies between 9 and 25 miles (15&#;40 km) above Earth&#;s surface.

Increases in sunburns and damage to the skin

Increases in mutations, since UV radiation causes changes in the DNA structure

A reduction in the growth of phytoplankton and the cumulative effect on food webs

A reduction in the effectiveness of the human body&#;s immune system

Use helium, ammonia, propane, or butane as a coolant alternative to HCFCs (hydrochlorofluorocarbons) and CFCs.

Offer tax credits or rebates for turning in old refrigerators and air conditioners.

Introduce tariffs on products produced in countries that allow the use of chlorofluorocarbons (CFCs).

Support legislation that reduces ozone-destroying chemicals in medical inhalers, fire extinguishers, aerosol hairsprays, wasp and hornet sprays, refrigerator and air conditioner foam insulation, and pipe insulation.

Greenhouse gases absorb this infrared radiation and trap the heat in the atmosphere.

When sunlight strikes Earth&#;s surface, some of it is reflected back toward space as infrared radiation (heat).

Greenhouse Gases by Source

Waste and wastewater : Landfill and wastewater methane (CH4), and incineration as a method of waste management.

Transportation : It involves fossil fuels that are burned for road, rail, air, and marine transportation.

Land use and forestry : It includes deforestation of old-growth forests (carbon sinks), land clearing for agriculture, strip-mining, fires, and the decay of peat soils

Industry : Primarily involves fossil fuels burned on-site at facilities for energy; cement manufacturing also contributes significant amounts of CO2 gas

Energy supply : The burning of coal, natural gas, and oil for electricity and heat is the largest single source of global greenhouse gas emissions.

Commercial and residential buildings : On-site energy generation and burning fuels for heat in buildings or cooking in homes

Agriculture : Mostly comes from the management of agricultural soils.

Greenhouse Gas Emissions by Gas

Black carbon (soot) : It is a solid particle or aerosol, not a gas, but it also contributes to the warming of the atmosphere.

Fluorinated gases : Industrial processes, refrigeration, and the use of a variety of consumer products all contribute to this gases, which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).

Fertilizer use is the primary source of nitrous oxide emissions.

Agricultural activities, waste management, and energy use all contribute to methane emissions.

Carbon dioxide (CO2) : It is an important heat-trapping (greenhouse) gas, and is released through human activities such as deforestation and burning fossil fuels, as well as natural processes such as respiration and volcanic eruptions.

9.4: Global Climate Change

• The world&#;s oceans contain more carbon dioxide than the atmosphere.

• Atmospheric temperatures, cloud cover, surface albedo, and water vapor cause pole-wide warming.

  • The north and south poles are warming faster because of energy in the atmosphere that is carried to the poles through large weather systems.

• Ocean currents carry heat around the Earth.

  • As the oceans absorb more heat from the atmosphere, sea surface temperatures rise and ocean circulation patterns change.

  • As the oceans store a large amount of heat, even small changes in these currents can have a large and lasting effect on the global climate.

• Air temperatures today average 5°F to 9°F (3°C to 5°C) warmer than they were before the Industrial Revolution.

  • Higher average air temperatures may increase the frequency or severity of storms, surface water/groundwater inputs, sedimentation in bodies of water, flooding and associated water runoff, and aquifer recharge.

• Global warming could completely change estuaries and coastal wetlands.

  • Sea-level rise threatens to inundate many coastal wetlands, threatening biota that cannot move inland due to coastal development.

• The UN estimates that 150 million people will need to be relocated worldwide by due to coastal flooding, shoreline erosion, and agricultural disruption.

• The total surface area of glaciers worldwide has decreased 50% since the end of the 19th century.

• The main ice-covered landmass is Antarctica at the South Pole, with about 90% of the world&#;s ice and 70% of its freshwater.

  • If all of the Antarctic ice melted, sea levels around the world would rise about 200 feet (60 m).

• Greenhouse gases trap solar radiation in the Earth&#;s atmosphere, making the climate warmer.

• Due to global warming, mosquitoes have more places to breed, which increases malaria, dengue fever, Zika virus, and yellow fever rates.

  • Warmer water may spread amoebic dysentery, cholera, and giardia because it increases bacterial activity.

• Higher air temperatures have been proven to result in higher incidences of heat-related deaths caused by cardiovascular disease, heat exhaustion, heat stroke, hyperthermia, and diabetes.

• Arctic fauna will be the most affected. The food webs of polar bears that depend on ice floes, birds, and marine mammals will be drastically affected.

• The movement of tectonic plates causes volcanoes and mountains to form, which can also contribute to changes in the climate

• Volcanic gases that reach the stratosphere have a long-term effect on climate.

• The fluctuations in the solar cycle impact Earth&#;s global temperature by ~0.1°, slightly hotter during solar maximums and slightly cooler during solar minimums.

• As rivers and streams warm, warm-water fish are expanding into areas previously inhabited by cold-water species.

• The Arctic region is a large natural source of methane.

  • Arctic methane release, caused by melting glaciers, creates a positive feedback loop because methane is a greenhouse gas.

• Sea levels have risen 400 feet (120 m) since the peak of the last ice age approximately 18,000 years ago.

  • From about 13,000 years ago to the start of the Industrial Revolution, sea levels rose 0.1 to 0.2 mm per year. Since , sea levels have risen about 3 mm per year.

• The amount of energy absorbed and stored by the oceans has an important role in the rise of sea levels due to thermal expansion.

• Ocean acidification: It occurs when atmospheric carbon dioxide reacts with seawater to form carbonic acid,

• Kyoto Protocol (): A plan created by the United Nations to reduce the effects of climate change, which results in a reduction in the pH of ocean water over an extended period of time.

• Montreal Protocol (): An international treaty designed to phase out the production of substances that are responsible for ozone depletion.

• Paris Agreement (): It deals with greenhouse gas emissions and mitigation.

  • The goal is to keep global temperature rise below 2°C above pre-industrial levels while each country determines its own plans to mitigate global warming.

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