AP Environmental Science Exam Review

Ionizing Radiation

• Definition: radiation with enough energy to dislodge electrons from atoms, creating ions.

• Examples: gamma rays, X-rays, UV radiation.

• Effect: capable of causing cancer.

High Quality Energy

• Definition: organized and concentrated energy that can perform useful work.

• Examples: fossil fuels and nuclear energy.

Low Quality Energy

• Definition: disorganized and dispersed energy.

• Examples: heat in the ocean or air, wind, solar energy.

First Law of Thermodynamics

• Statement: energy is neither created nor destroyed, but can be converted from one form to another.

• Also known as: Law of Conservation of Energy.

Second Law of Thermodynamics

• Statement: when energy changes form, some useful energy is always degraded into lower quality energy, typically heat.

Natural Radioactive Decay

• Definition: unstable radioactive isotopes release gamma rays, alpha particles, and beta particles.

• Example: Radon.

Half-Life

• Definition: the time it takes for half the mass of a radioactive isotope to decay.

Radioactive Isotope Storage

• Rule of thumb: a radioactive isotope should be stored for approximately 10 half-lives to decay to a safe level.

Nuclear Fission

• Definition: the nuclei of isotopes split apart when struck by neutrons.

Nuclear Fusion

• Definition: two isotopes of light elements (hydrogen) are forced together at high temperatures to form a heavier nucleus (helium).

• Status: expensive, break-even point not yet reached.

• Occurrence: happens in the Sun.

Ore

• Definition: rock with a high enough concentration of a mineral to be profitable to mine.

Mineral Reserve

• Definition: identified mineral deposits that are currently profitable to extract.

Best Solution to Energy Shortage

• Options: conservation, increased efficiency, explore alternative energy sources.

Organic Fertilizer

• Characteristics: slow-acting and long-lasting due to the time needed for organic remains to decompose.

Surface Mining

• Advantages: cheaper, can remove more minerals, less hazardous to workers.

Humus

• Definition: organic, dark material remaining after decomposition by microorganisms.

Leaching

• Definition: removal of dissolved materials from soil by water moving downwards.

Illuviation

• Definition: deposit of leached material in lower soil layers (B Horizons).

Loam

• Definition: ideal agricultural soil with optimal proportions of sand, silt, and clay (40%, 40%, 40%).

Soil Conservation Methods

• Examples: conservation tillage, crop rotation, contour plowing, organic fertilizers.

Soil Salinization

• Definition: in arid regions, water evaporates, leaving salts behind.

• Example: Fertile Crescent.

Conservation

• Definition: using resources in a responsible manner.

Preservation

• Definition: setting aside areas and protecting them from human activities.

Water Logging

*Definition: saturation of soil with water, depriving plant roots of oxygen and causing them to rot.

Hydrologic Cycle Components

• Elements: evaporation, transpiration, runoff, condensation, precipitation, and infiltration.

Watershed

• Definition: all the land that drains into a body of water.

Aquifer

• Definition: underground layers of porous rock that allow water to move slowly.

Cone of Depression

• Definition: lowering of the water table around a pumping well.

Salt Water Intrusion

• Definition: near the coast, overpumping of groundwater causes saltwater to move into the aquifer.

ENSO: El Nino Southern Oscillation

• Definition: see-sawing of air pressure over the South Pacific.

El Nino Year

• Characteristics: trade winds weaken, warm water moves towards South America.

• Effects: diminished fisheries off South America, drought in western Pacific, increased precipitation in southwestern North America, fewer Atlantic hurricanes.

Effects of El Nino

• Upwelling decreases, disrupting food chains.

• Northern US has mild winters, Southwest US has increased rainfall.

• Fewer Atlantic hurricanes.

La Nina

• Definition: “Normal” year with easterly trade winds, warm water in the western Pacific, upwelling off the West Coast of South America.

Nitrogen Fixation

• Process: atmospheric nitrogen is converted into ammonia by bacteria, making it usable by plants.

Ammonification

• Definition: decomposers convert organic waste into ammonia.

Nitrification

• Process: ammonia is converted to nitrate ion $(NO_3^{-1})$.

Assimilation

• Process: inorganic nitrogen is converted into organic molecules such as DNA, amino acids, and proteins.

Denitrification

• Process: bacteria convert nitrate $(NO<em>3)^{-1}$ and nitrite $(NO</em>2)^{-1}$ back into $N_2$ gas.

Phosphorus Cycle

• Difference from nitrogen cycle: phosphorus does not exist as a gas; it's released by weathering of phosphate $(PO_4)^{-3}$ rocks.

• Speed: slow cycle and not atmospheric.

Phosphorus as a Limiting Nutrient

• Role: major limiting nutrient in plant growth.

Phosphorus in aquatic ecosystems

• Sources: runoff of animal wastes, fertilizer, discharge of sewage.

Sustainability

• Definition: the ability to meet current needs without compromising the ability of future generations to meet their needs.

Photosynthesis

• Process: plants convert $CO<em>2$ (atmospheric carbon) into complex carbohydrates (sugars) (glucose $C</em>6H<em>{12}O</em>6$).

Aerobic Respiration

• Process: oxygen-consuming producers, consumers, and decomposers break down complex organic compounds and convert carbon back into $CO_2$.

Largest Reservoirs of Carbon

• Ranked: carbonate $(CO_3)^{-2}$ rocks, oceans.

Biotic

• Definition: the living component of an ecosystem.

Abiotic

• Definition: non-living component of an ecosystem.

Producer/Autotroph

• Definition: organisms that make their own food—photosynthetic or chemosynthetic life.

Trophic Levels

• Order: producers → primary consumer → secondary consumer → tertiary consumer.

Energy Flow in Food Webs

• Rule: only 10% of the usable energy is transferred to the next trophic level.

• Reason: usable energy is lost as heat (Second law of thermodynamics); not all biomass is digested and absorbed; predators expend energy to catch prey.

Succession

• Definition: the gradual colonization of a habitat after an environmental disturbance.

Primary Succession

• Definition: development of communities in a lifeless area not recently inhabited by life or where soil is completely destroyed.

• Example: retreating glacier, lava flows.

• Begins with: lichen action.

Secondary Succession

• Definition: life progresses where soil remains.

• Examples: clear-cut forest, vacant lot, old farm or fire.

Climax Community

• Definition: the stable, final community that develops from ecological succession.

Symbiosis

• Definition: occurs when members of two different species live in close physical contact with each other.

Mutualism

• Definition: symbiotic relationship where both organisms benefit.

Commensalism

• Definition: symbiotic relationship in which one organism benefits and the other organism isn’t affected.

Parasitism

• Definition: relationship in which one organism (the parasite) obtains nutrients at the expense of the host.

Biomes

• Definition: large distinct terrestrial region having similar climate, soil, plants, and animals.

Carrying Capacity

• Definition: the number of individuals that can be sustained in an area.

R strategist

• Characteristics: reproduce early; bear many small, unprotected offspring.

• Examples: insects, mice.

K strategist

• Characteristics: reproduce late in life; few offspring; care for offspring.

Positive Feedback

• Definition: a change in some conditions triggers a response that intensifies the changing condition.

• Example: Warmer Earth → snow melts → less sunlight is reflected and more is absorbed → warmer Earth.

Negative Feedback

• Definition: a change in some condition triggers a response that counteracts the changed condition.

• Example: Warmer Earth → more ocean evaporation → more stratus clouds → less sunlight reaches the ground → cooler Earth.

Natural Selection

• Definition: organisms that possess favorable adaptations (traits) are more likely to survive and pass them onto the next generation, leading to higher reproductive success.

Exotic Species/Invasive Species

• Definition: non-native species to an area that often thrive and disrupt the ecosystem balance.

• Examples: African Honeybee, Fire Ant, Zebra Mussel, Purple Loosestrife.

Doubling Time

• Rule of 70: doubling time equals 70 divided by the percent growth rate ($Doubling Time = <br>70 / Growth Rate$).

• Example: if a population is growing at 5% annually, it doubles in 14 years ($<br>70/5 = 14$ years).

Replacement Level Fertility

• Definition: the number of children a couple must have to replace themselves.

• Averages: averages 2.1 in developed nations, 2.7 in less developed nations.

World Population

• Approximately 7.5 billion as of the transcript creation.

U. S. Population

• Approximately 327 million as of the transcript creation.

DEMOGRAPHIC TRANSITION MODEL

• Preindustrial Stage: birth and death rates high, population grows slowly, infant mortality high

• Transitional Stage: death rate (infant mortality) lower, birth rates remain high, better health care, population grows fast.

• Industrial Stage: decline in birth rate, population growth slows

• Postindustrial state: low birth rate and low death rate

• Age Structure Diagram: broad base→ rapid growth; narrow base→ negative growth; uniform shape→ zero growth

• Top Four Most Populated Nations: 1) China; 2) India; 3) U.S. and ) Indonesia

• Most Important Thing Affecting Population Growth: low status of women

• Methods or Ways to Decrease Birth Rate: family planning; contraception, economic rewards and penalties

Composition of Water on Earth

• 97.5% Seawater; 2.5% freshwater

• 81: Ways to conserve water: Agriculture: drip/trickle irrigation; Industry: recycling; Home: use gray water, repair leaks, low flow fixtures, different types of yard (zeroscape not planting Kentucky Blue grass), time of day watering…

• 82: Gray Water: Any wastewater from a house EXCEPT TOILIET WATER; (dish water, shower water…) this water can be used for irrigation water…

• Aquaculture: farming aquatic species, commonly salmon, shrimp, tilapia, oysters.

Water Pollution

• Point Source: source from specific location such as pipe or smokestack

• Non-point Source: (Area/Dispersed Source): source spread over an area such as agricultural/feedlot runoff, urban runoff, and traffic runoff.

• Primary Sewage Treatment: first step of sewage treatment; eliminates most particulate material from raw sewage using grates, screens, and gravity (settling).

• Secondary Sewage Treatment: second step of sewage treatment; bacteria breakdown organic waste; aeration accelerates the process.

• BOD: (Biological Oxygen Demand), amount of dissolved oxygen needed by aerobic decomposers to break down organic materials.

• Eutrophication: rapid algal growth (algal bloom) caused by an excess of nitrogen and phosphorous, blocks sunlight, causing the death/decomposition of aquatic plants, decreasing dissolved oxygen (DO), suffocating fish. The rapid growth is caused by an excess nitrates (NO3)-1 , and phosphates (PO4)3- in water.

• Hypoxia: water with very low dissolved oxygen levels, the end result is eutrophication. The BOD rises as aerobic decomposers breakdown the plants , the dissolved oxygen (DO) drops and the water cannot support life.

• Fecal coliform (Enterrococus bacteria): Coccus (round shaped bacteria); indicator of sewage contamination (Happens over the summer at Chatfield or Cherry Creek Reservoir once in a while.)

• Chlorine: Good: disinfection of water; Bad: forms trihalomethanes (this group of compounds are byproducts of chlorination and are known carcinogens)

• Minamata Disease: (1932-1968 Japan) mental impairments caused by methylmercury (CH3Hg)+1 poisoning

• CAFÉ standards: Corporate Average Fuel Economy : standards enacted into law in 1975, established fuel efficiency standards for passenger cars and light trucks. The fuel economy ratings fro a manufacture’s entire line of passenger cars must currently average at least 27.6 mpg for the manufacturer to comply with the standard.

Air Pollution

• Primary Air Pollutants: produced by human and nature (CO, CO2, SOx NOx,hydrocarbons, particulates)

• Secondary Pollutants: formed by reaction of primary pollutants.

• Particulate Matter:

  • Source: burning fossil fuels and diesel exhaust

  • Effects: reduces visibility and respiratory irritation

  • Reduction: filtering, electrostatic precipitators, alternative energy

• Nitrogen Oxides: (NOx)

  • Source : auto exhaust

  • Effects: acidification of lakes, respiratory irritation, leads to smog and ozone

  • Equation For Acid Formation: NO + O2 → NO2 + H2O → HNO3

  • Reduction: Catalytic Converter

• Sulfur Oxides: (SOx)

  • Source: coal burning

  • Effects: acid deposition, respiratory irritation, damages plants

  • Equation for acid formation: SO2 +O2→ SO3 + H2O → H2SO4

  • Reduction: scrubbers, burn low sulfur fuels

• Carbon Dioxide (CO2)

  • Source: combustion of fossil fuels

  • Effects: greenhouse gas—contributes to global warming

  • Reduction: accomplished by increased fuel efficiency (gas mileage) mass transit (reduction)

• Carbon Monoxide: (CO)

  • Sources: include incomplete combustion of fossil fuels.

  • Effects: binds to hemoglobin reducing bloods ability to carry O2

  • Reduction: accomplished by catalytic converters, oxygenated fuel, mass transit (reduction)

• Ozone: (O3)

  • Formation: secondary pollutant

  • Equation: NO2 + UV → NO + O; O + O2 → O3, with VOC’s (Volatile Organic Compounds)

  • Effects: respiratory irritant, plant damage

  • Reduction: reduce NO and VOC emissions

• Radon: (Rn): naturally occurring colorless, odorless, radioactive gas, found in some types of soil and rock, can seep into homes and buildings, formed from the decay of uranium (U), causes lung cancer

• Photochemical Smog: formed by chemical reactions involving sunlight (NO, VOC,O/O2)

• Acid Deposition: caused by sulfuric and nitric acids resulting in lower pH of surface waters.

• 106: Greenhouse Gases: Most significant: H2O, CO2, methane (CH4), CFC’s. Trap outgoing infrared energy (heat) causing Earth to warm.

• Effects of Global Warming: rising sea level (due to thermal expansion not melting ice), extreme weather, drought, famine, extinctions.

• Greenhouse Effect: a vital process, required for life to exist on Earth. If accelerated, bad, leads to global warming.

• Ozone Depletion: caused by CFC’s, methyl chloroform, carbon tetrachloride, halon (haloalkanes), methyl bromide all of which attack the stratospheric ozone.

• Effects of Ozone Depletion: include increased UV, skin cancer, cataracts, and decreased plant growth.

• Love Canal, NY: (1950’s +) chemicals buried in old canal; school and homes built over it; caused birth defects and cancer.

• Main Components of Municipal Solid Waste: is mostly paper and mostly put in the landfills.

• Sanitary Landfill Problem and Solutions

  • problem= leachate; solution= linear collection system

  • problem=methane gas; solution= collect gas and burn

  • problem=volume of garbage; solution= compacted and reduce

• Incineration Advantages: volume of waste reduced by 90% and waste heat can be used. The process that uses waste heat to generate electricity is called Cogeneration.

• Incineration Disadvantages: toxic emissions (polyvinyl chloride, dioxins), scrubbers and electrostatic precipitators needed, ash disposal (contains heavy metals)

• Best Way To Solve Waste Problems: reduce the amounts of waste at the source

• True Cost/External Cost: harmful environmental side effects that are not reflected in the product’s price.

• 118: Brownfield: is an abandoned industrial site.

• Keystone Species: species whose role in an ecosystem is more important than others. Examples are Sea Otter, Sea Stars, Grizzly Bear, Prairie Dogs.

• Indicator Species: species that serve as early warnings that an ecosystem is being damaged (ex. trout)

• In Natural Ecosystems, Methods Which Control 50-90% Of Pests: Predators, Disease, Parasites

• Major Insecticide Groups: chlorinated hydrocarbons (ex DDT); organophosphates (ex malathion); carbamates (ex aldicarb)

• Presticides:

  • Pro: saves lives from insect-transmitted disease, increased food supply, increases profits for farmers.

  • Con: genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, biological magnification.

• Pesticides: Con: genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, biological magnification.

• Natural Pest Control: better agricultural practices, genetically resistant plants, natural enemies, and biopesticides, sex attractants.

• Genetically Modified Organisms: (GMOs): new organisms created by altering the genetic material (DNA) of existing organisms; usually in attempt to remove undesirable or create desirable characteristics in the new organism.

• Electric Generation Methods: steam, from water boiled by fossil fuels or nuclear energy, or falling water is used to turn a turbine and that turns a generator to generate electricity.

• Petroleum (Crude Oil) Formation: microscopic aquatic organisms in sediments are converted by heat and pressure into a mixture of hydrocarbons.

• Pros of Petroleum: cheap, easily transported, high quality energy.

• Cons of Petroleum: reserves will be depleted soon; pollution during drilling, transport and refining, burning makes CO2.

• Coal Formation: prehistoric plants buried un-decomposed in oxygen-depleted water of swamps/bogs converted by heat and pressure.

• Ranks of Coal: Peat, Lignite, Bituminous coal, anthracite coal. (Best to worst)

• Major Nuclear Reactor Components: consists of a core, control rods, moderator, steam generator, turbine, containment building.

• Two Most Serious Nuclear Accidents: Chernobyl, Ukraine (1986), and Three Mile Island, PA (1979)

• Alternative Energy Sources: wind, solar, waves, biomass, geothermal, fuel cells.

• Remediation: return a contaminant area to its original state.

• LD 50 (LD-50, LD50): the amount of a chemical that kills 50% of the animals in test population.

• Mutagen: causes changes to DNA that may result in hereditary changes; Teratogen: causes fetus deformities (birth defects), Carcinogen: substance that causes cancer.

• Threshold Dose: the maximum dose that has no measurable effect.

• Major Source of Sulfur: burning coal; (new article cruise ships)

• Sources of Mercury: burning coal, compact fluorescent bulbs.

• Volcano and Earthquake Occurrence: at plate boundaries (divergent plate boundary=spreading, new crust being formed, example-- mid-ocean ridges) (convergent plate boundaries= trenches, tectonic plates with the oldest crustal material on Earth moving together, one moving under another; mid-oceanic trenches) (transform plate boundary=sliding, tectonic plates sliding by one another, San Andreas Fault in California)

• The Tragedy of the Commons: (1968 paper by ecologist Garret Hardin) global commons such as atmosphere and oceans are used by all and owned by none.

• Forest Fires

  • Types: Surface: usually burn only under growth and leave litter on forest floor; Crown hot fires, may start on ground but eventually leap from treetop to treetop; Ground go underground, may smolder for days or weeks, difficult to detect and extinguish i.e. peat bogs.

• Food: Wheat, rice, and corn provide more than ½ of the calories in the food consumed by the world’s people.

• Monoculture: cultivation of a single crop, usually in a large area.

• Temperature Inversion: layer of dense, cool air trapped under a layer of warm dense air, pollution in trapped layer may build to harmful levels. Frequent in Los Angeles, California; Mexico City, Mexico; often in Denver, Colorado.

• Transpiration: process where water is absorbed by plant roots (caused by difference in pressure (Soil higher pressure and atmosphere lower pressure, water moves up through plants, passes though pores called stomata in leaves or other parts, evaporates into the atmosphere as water vapor. Hydrogen bonding, cohesion and adhesion help water move up a plant.

• Troposphere: first layer of the atmosphere, 0-10 miles above Earth’s surface. Contains weather, greenhouse gases (bad ozone).

• Stratosphere: second layer of atmosphere, 10-30 miles above Earth’s surface. Contains protective ozone layer (good ozone).

• Dioxin: one of the most toxic human-made chemicals. Stable, long-lived, by-product of herbicide production enters the environment as fallout from the incineration of municipal and medical waste and persists for many years.

• PCB’s: (Polychlorinated Biphenyls): Stable, long-lived, carcinogenic chlorinated hydrocarbons. Produced by the electronics industry.

• Multiple Use Public Lands: National Forest and National Resource Land

• Moderately Restricted Use Public Lands: National Wildlife Refuges

• Restricted Use Public Lands: National Parks and National Wilderness Preservation System

Endangered Species

• Defined: A group of organisms in a danger of becoming extinct if the situation is not improved; population numbers have dropped below the critical number of organisms.

• Characteristics: Most have a small range, require a large amount of territory, have long generations, have a very specialized niche, or live within an island.

• Examples:

  • Atlantic Salmon: interbreeding with competition from escaped farm-raised salmon from the aquaculture industry threaten the wild salmon population.

  • California Condor: reason for decline include shootings, poisoning, lead poisoning, collisions with power lines, egg collecting , pesticides, habitat loss, and the decline of large and medium-sized native mammals due to encroachments of agriculture and urbanization.

  • Delhi Sands Flower-Loving Fly: a one inch long insect currently restricted to only 12 known populations in San Bernardino and Riverside counties. An estimated 98% of its habitat has been converted to residential, agricultural, and commercial use.

  • Florida Panther: hunting and development that resulted in habitat loss and fragmentation

  • Grizzly Bear: conflict with humans and development that resulted in habitat loss and fragmentation.

  • Gray Wolf: subject of predator eradication programs sponsored by the Federal government. Prior to Endangered Species Act of 1973, exterminated from lower 48 states except for a few hundred inhabiting extreme northeastern Minnesota, and a small number on Isle Royale, Michigan.

  • Whooping Crane: drainage of wetlands, conversion of grasslands to agriculture, and for hunting feathers.

  • Manatee: Initial population decreases resulted from overharvesting for meat, oil and leather. Today, heavy mortality occurs from accidental collusions with boats and barges, and from canal lock operations.

• Not Endangered Species

  • American Alligator: overhunting and destruction of habitat caused original listing, removed from the list of the endangered species by the Fish and Wildlife Service in 1987.

  • Bald Eagle: ingested DDT by eating contaminated fish. The pesticide caused the shells of the bird’s to thin and resulted in nesting failures. Loss of nesting habitats and hunting for feathers also contributed to the population decline. Reclassified from endangered to threatened in 1995.

  • Peregrine Falcon: ingested DDT by eating smaller birds, which had eaten contaminated prey. The pesticide caused the shells of the birds to thin and resulted in nesting failures. Removed from the list of endangered species by the Fish and Wildlife Service in 1999.

  • Gray Whale: the eastern Northern Pacific stock in gray whale has the distinction of being the first population of a marine mammal species to be removed from the List of Endangered and Threatened Species.

Biomes

• Defined: large distinct terrestrial region having similar climate, soil, plants and animals.

• Examples:

  • Tropical Rain Forest: characterized by the greatest diversity of species, believed to include many undiscovered species. Occur near the equator. Soil tends to be low in nutrients. Distinct seasonality: winter is absent and only two seasons are present (rainy and dry).

  • Temperate Forests: occur in eastern North America, Japan, northeastern Asia, and western and central Europe. Dominated by tall deciduous trees. Well-defined seasons include a distinct winter. Logged extensively, only scattered remnants of original temperate forest remain.

  • Boreal Forests or Taiga: represents the largest terrestrial biome. Dominated by needleleaf, coniferous trees. Found in the cold climates of Eurasia and North America: two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada. Seasons are divided into short moist, and moderately warm summers, and long, cold, and dry winters. Extensive logging may soon cause their disappearance.

  • Temperate Shrub Lands or Chaparral: occurs along the coast of Southern California and the Mediterranean region. Characterized by areas of Chaparral—miniature woodlands dominated by dense stands of shrubs.

  • Savannas: grassland with scattered individual trees. Cover almost half of the surface of Africa and large areas of Australia, South America, and India. Warm or hot climates where the annual rainfall is 20-50 inches per year. The rainfall is concentrated in a six to eight month period of the year, followed by a long period of drought when fires can occur.

  • Temperate Grasslands: dominated by grasses, trees and large shrubs are absent. Temperature vary more from summer to winter, and the amount of rainfall is less than in savannas. Temperate grasslands have hot summers and cold winters. Occur in South Africa, Hungary, Argentina, the steppes of the former Soviet Union, and the plains and prairies of central North America.

  • Deserts: covers about one fifth of the Earth’s surface and occur where rainfall is less than 50 cm a year (less than 20 inches a year). Most deserts occur at low latitudes, have a considerable amount of specialized vegetation, as well as specialized animals. Soils have abundant nutrients, need only water to become productive, and have little or no organic matter. Common disturbances include occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.

  • Tundra: treeless plains that are the coldest of all the biomes. Occur in the artic and Antarctica. Dominated by lichens, mosses, sedges, and dwarfed shrubs. Characterized by extremely cold climate, permanently frozen ground (permafrost) low biotic diversity, simple vegetation structure, limitation of drainage, short seasons of growth and reproduction.

  • Wetlands: areas of standing water wet all or most of the year that support aquatic plants including marshes, swamps, and bogs. Species diversity is very high. Includes bogs, swamps, sloughs, marshes.

  • Fresh Water: defined as having a low salt concentration (less than 1%). Plants and animals have adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e. oceans). There are different types of freshwater regions: ponds and lakes, streams, and rivers and estuaries.

  • Oceans: the largest of all of the ecosystems. The ocean regions are separated into separate zones: intertidal, pelagic, abyssal, and benthic. All four zones have a great diversity of species.

Places to Know

• Chernobyl, Ukraine: April 26, 1986, unauthorized safety test (irony), leads to fire and explosion at nuclear power plant—millions exposed to unsafe levels of radiation.

• Three-Mile Island, Pennsylvania: March 29, 1979, nuclear power plant loses cooling water, 50% of core melts, radioactive materials escape into the atmosphere, near meltdown (disaster).

• Yucca Mountain, Nevada: controversial as proposed site for permanent storage of high-level nuclear waste, 70-miles northwest of Las Vegas, near volcano and earthquake faults.

• Aral Sea: Uzbekistan/Kazakhstan (former Soviet Union): large inland sea is drying up as a result of water diversion.

• Love Canal, NY: chemical buried in old canal, school and homes built over it led to birth defects and cancers.

• Aswan High Dam, Egypt: the silt that made the Nile region fertile fills the reservoir. Lack of irrigation controls causes waterlogging and salinization. The parasitic disease schistosomiasis thrives in stagnant water of the reservoir.

• Three Gorges Dam, China: world’s largest dam on Yangtze River will drown ecosystems, cities, archeological sites, fragment habitats, and displace 2 million people.

• Ogallala Aquifer: world’s largest aquifer; under parts of Wyoming, South Dakota, Nebraska, Kansas, Colorado, Oklahoma, New Mexico and Texas. Hold enough water to cover the U.S. with 1.5 feet of water. Being depleted for agricultural and urban use.

• Minamata, Japan: mental impairments, birth defects, and deaths caused by mercury dumped in the Minamata Bay by a factory. Mercury entered humans through their diet (fish).

• Bhopal, India: December 2, 1984, methyl isocyanate released accidentally by Union Carbide pesticide plant kills over 5,000.

• Valdez, Alaska: March 24, 1989: tanker Exxon Valdez hits submerged rocks in Prince William Sound—Worst Oil Spill in US waters.

People to Know

• Rachel Carson: published Silent Spring in 1962; documented the environmental damage done by DDT and other pesticides. Which heightened public awareness at the start of the modern environmental movement.

• John Muir: founded Sierra Club in 1892; fought unsuccessfully to prevent damming of the Hetch Hetchy Valley in Yosemite National Park.

• Gifford Pinchot: the first chief of the US Forest Service; advocated managing resources for multiple use using principles of sustainable yield.

• Garrett Hardin: published “The Tragedy of the Commons” in the journal of Science in 1968; argued that rational people will exploit shared resources (commons).

• Aldo Leopold: wrote A Sand County Almanac published the year after his death in 1948; promoted a “Land Ethic” in which humans are ethically responsible for serving as the protectors of nature.

• Sherwood Rowland and Mario Molina: in 1974, determined that CFC’s destroy stratospheric (good) ozone.

• Thomas Malthus: said: “human population cannot continue to increase exponentially; consequences will be war, famine and pestilence (disease).

Legislation and International Treaties: Note Year of Inception

• Mining

  • Surface Mining Control And Reclamation Act (1977): requires coal strip mines to reclaim the land

  • Madrid Protocol (1991): Suspension of mineral exploration (mining) for 50 years in Antarctica

• Water

  • Safe Drinking Water Act (SDWA, 1974): set maximum contaminant levels for pollutants in drinking water that may have adverse effects on human health.

  • Clean Water Act (CWA, 1972): set maximum permissible amounts of water pollutants that can be discharged into waterways; aims to make surface waters swimmable and fishable.

  • Ocean Dumping Ban Act (1988): bans ocean dumping of sewage sludge and industrial waste in the ocean.

  • National Wild and Scenic Rivers Act: () protects rivers with due to aesthetic, recreational, wildlife, historical, or cultural reasons.

• Air

  • Clean Air Act: (CAA, 1970): set emission standards for cars and limits for release of air pollutants.

  • Kyoto Protocol: (2005): controlling global warming by setting greenhouse gas emissions targets for developed countries.

  • Montreal Protocol: (1987): phase-out of ozone depleting substances.

• Waste

  • Resource Conservation and Recovery Act (RCRA): (1976): controls hazardous waste with a cradle to grave system.

  • Comprehensive Environmental Response, Compensation and Liability Act (CERCLA): (1980): “Superfund”, designed to identify and clean up abandoned hazardous waste dump sites.

  • Nuclear Waste Policy Act: (1982): U.S. government must develop a high level of nuclear waste site by 2015 (Yucca Mtn.)

  • Low-Level Radioactive Policy Act: all states must have facilities to handle low-level radioactive wastes.

• Life and Land

  • Endangered Species Act: (1973): identifies threatened and endangered species in the U.S. and puts their protection ahead of economic considerations.

  • Convention on International Trade in Endangered Species (CITIES): (1973): lists species that cannot be commercially traded as live specimens or wildlife products.

  • Magnuson-Stevens Act: (1976): Management of Marine Species

  • Food Quality Protection Act: (1996): set pesticide limits in food and all active and inactive ingredients must be screened for estrogenic and endocrine effects.

  • Lacey Act (1900) prohibits interstate transport of wild animals

Ionizing radiation is defined as radiation with enough energy to dislodge electrons from atoms, creating ions. Examples of ionizing radiation include gamma rays, X-rays, and ultraviolet (UV) radiation, which can be capable of causing cancer.

High-quality energy is defined as organized and concentrated energy that can perform useful work, with fossil fuels and nuclear energy serving as prominent examples. In contrast, low-quality energy is characterized as disorganized and dispersed energy, like heat in the ocean or air, wind, and solar energy.

The first law of thermodynamics states that energy is neither created nor destroyed but can be converted from one form to another, which is often referred to as the law of conservation of energy. The second law of thermodynamics states that when energy changes form, some useful energy is invariably degraded into lower quality energy, typically in the form of heat.

Natural radioactive decay involves unstable radioactive isotopes releasing gamma rays, alpha particles, and beta particles, with radon being a common example. The half-life of a radioactive isotope is the time it takes for half the mass of that isotope to decay. It is often advised to store radioactive isotopes for approximately 10 half-lives to decay to a safe level.

Nuclear fission is defined as the splitting of the nuclei of isotopes when struck by neutrons, whereas nuclear fusion involves two isotopes of light elements, such as hydrogen, being forced together at high temperatures to form a heavier nucleus, like helium. Nuclear fusion is still considered expensive, with the break-even point not yet reached, but it occurs naturally in the Sun.

An ore is defined as rock containing a high enough concentration of a mineral to be profitable to mine, while a mineral reserve refers to identified mineral deposits that are currently profitable to extract. The best solutions to an energy shortage include conservation, increased efficiency, and exploring alternative energy sources.

Organic fertilizers are characterized by their slow-acting and long-lasting nature due to the time needed for organic remains to decompose. Surface mining offers advantages such as lower costs, the potential to remove more minerals, and being less hazardous to workers. Humus is the organic, dark material that remains after decomposition by microorganisms, while leaching refers to the removal of dissolved materials from soil by water moving downwards. Illuviation is the deposit of leached material in lower soil layers, specifically the B horizons. Loam, which is considered ideal agricultural soil, consists of optimal proportions of sand (40%), silt (40%), and clay (20%).

Soil conservation methods like conservation tillage, crop rotation, contour plowing, and the use of organic fertilizers are essential in managing soil health. Soil salinization occurs in arid regions where water evaporates and leaves salts behind, with the Fertile Crescent serving as an example. Conservation is defined as using resources responsibly, while preservation involves setting aside areas and protecting them from human activities. Water logging is defined as the saturation of soil with water, which deprives plant roots of oxygen and causes them to rot.

The hydrologic cycle comprises components such as evaporation, transpiration, runoff, condensation, precipitation, and infiltration. A watershed is defined as all the land that drains into a body of water, while an aquifer refers to underground layers of porous rock that allow water to move slowly. The cone of depression is the lowering of the water table around a pumping well, and saltwater intrusion describes the movement of saltwater into an aquifer due to over-pumping of groundwater near the coast.

The El Nino Southern Oscillation (ENSO) is characterized by the see-sawing of air pressure over the South Pacific, famously resulting in trade winds weakening and warm water migrating toward South America during an El Nino year. This phenomenon causes diminished fisheries off South America, droughts in the western Pacific, increased precipitation in southwestern North America, and fewer Atlantic hurricanes. The associated effects disrupt food chains, leading to decreased upwelling and variable winters in the Northern U.S. In contrast, La Nina refers to a “normal” year characterized by consistent easterly trade winds and warm water concentrated in the western Pacific, resulting in upwelling off the West Coast of South America.

Nitrogen fixation is a process involving the conversion of atmospheric nitrogen into ammonia by bacteria, making it usable by plants. Ammonification is when decomposers convert organic waste into ammonia, while nitrification is the process where ammonia is converted to nitrate ions (NO₃⁻). Assimilation occurs when inorganic nitrogen is converted into organic molecules such as DNA, amino acids, and proteins. Denitrification involves bacteria converting nitrate (NO₃⁻) and nitrite (NO₂⁻) back into nitrogen gas (N₂).

The phosphorus cycle distinctly differs from the nitrogen cycle in that phosphorus does not exist as a gas; it is released through the weathering of phosphate rocks (PO₄³⁻) and operates more slowly without atmospheric involvement. As a major limiting nutrient in plant growth, phosphorus plays a critical role. In aquatic ecosystems, phosphorus sources include runoff from animal waste, fertilizers, and sewage discharge. Sustainability refers to the ability to meet current needs without compromising future generations' ability to meet theirs.

Photosynthesis is the process through which plants convert CO₂ into complex carbohydrates (sugars), primarily glucose (C₆H₁₂O₆). Aerobic respiration is when oxygen-consuming producers, consumers, and decomposers break down complex organic compounds, reverting carbon back into CO₂. Carbon is stored primarily in carbonates (CO₃²⁻) and oceans, which serve as the largest reservoirs.

In ecosystems, biotic refers to the living components while abiotic pertains to non-living factors. Producers or autotrophs are organisms that generate their own food, typically through photosynthesis or chemosynthesis. The trophic levels in a food web follow the order: producers, primary consumers, secondary consumers, and tertiary consumers. Energy flow in food webs follows the 10% rule whereby only 10% of usable energy is passed to the next trophic level due to energy loss as heat and unconsumed biomass.

Succession denotes the gradual colonization of a habitat following an environmental disturbance, with primary succession referring to development in a lifeless area while secondary succession indicates life progression where soil remains. The climax community is the stable final set of organisms in an ecological succession.

Symbiosis occurs when members of different species live closely together, encompassing mutualism (where both organisms benefit), commensalism (one benefits, the other is unaffected), and parasitism (one benefits at the host's expense). Biomes represent large distinct terrestrial regions characterized by similar climate, soil, plants, and animals.

Carrying capacity is the maximum number of individuals that an area can sustain. R strategists typically reproduce early and have many small offspring, while K strategists reproduce later and care for fewer offspring.

Positive feedback mechanisms promote further change, such as warmer environments prompting more snowmelt, while negative feedback works to counteract changes like increased ocean evaporation leading to more clouds and less sunlight reaching the ground. Natural selection fosters the survival of organisms with favorable adaptations, enhancing their reproductive success. Exotic or invasive species, which disrupt the ecosystem balance and thrive in new environments, serve as a significant ecological concern.

The doubling time rule, derived from a growth rate percentage, estimates how long it will take for a population to double. Replacement level fertility refers to the number of births needed for a population to replace itself, averaging around 2.1 in developed nations and 2.7 in less developed ones. The world population sits at approximately 7.5 billion, with the U.S. population around 327 million as of the note's creation.

The demographic transition model outlines four stages, from the preindustrial stage with high birth and death rates to a postindustrial state characterized by low rates. Key factors affecting population growth include the low status of women, with methods to decrease birth rates including family planning, contraception, and economic incentives.

About 97.5% of Earth’s water is seawater, while only 2.5% is freshwater. Conservation methods include techniques like drip irrigation in agriculture, recycling in industry, and utilizing gray water or low-flow fixtures at home. Gray water refers to any wastewater from a home except toilet water at times, which can be used for irrigation.

Water pollution is categorized into point source pollution (from specific locations) and non-point source pollution (spread across areas). Sewage treatment includes primary treatment, which removes particulate matter, and secondary treatment, where bacteria breaks down organic waste. Biological Oxygen Demand (BOD) measures the oxygen needed by aerobic decomposers, while eutrophication results from nitrogen and phosphorus excess, leading to algal blooms and decreased oxygen levels, ultimately causing hypoxia, which compromises aquatic life.

Indicators like fecal coliform (Enterococcus bacteria) reflect sewage contamination, and chlorine is an essential disinfectant that may also produce harmful byproducts. Minamata disease arises from methylmercury poisoning, while CAFÉ standards establish fuel efficiency regulations for vehicles.

Primary air pollutants originate from both human and natural activities, while secondary pollutants form from the reactions of primary pollutants. Specific pollutants such as particulate matter, nitrogen oxides, and sulfur oxides have defined sources and reduction strategies. Carbon dioxide and monoxide are recognized for their greenhouse effects and health impacts, while ozone is a significant secondary pollutant affecting respiratory health. Radon is a naturally occurring radioactive gas that poses health risks, and photochemical smog indicates chemical reactions facilitated by sunlight.

Greenhouse gases are key contributors to global warming, and ozone depletion results from substances like CFCs, leading to increased UV exposure and health issues. The Love Canal incident reflects the environmental impact of industrial waste, while municipal solid waste primarily consists of paper in landfills. Sanitary landfill issues pertain to leachate and methane gas with various solutions provided. Incineration poses advantages and disadvantages, including waste volume reduction and toxic emissions.

The best strategy for resolving waste issues emphasizes reducing waste generation at the source. True cost encompasses environmental side effects not captured in product pricing, while brownfields denote abandoned industrial sites. Keystone species greatly impact ecosystem stability, whereas indicator species signal environmental health. In natural ecosystems, pest control methods rely predominantly on intrinsic community dynamics.

Major insecticide classifications include chlorinated hydrocarbons, organophosphates, and carbamates, each with pros and cons. Natural pest management approaches promote practices like genetic resistance in plants. Genetically modified organisms (GMOs) arise from altering existing organisms' genetic make-up to create desired traits. Electric generation methods harness steam from various energy sources to produce electricity, with petroleum deriving from ancient aquatic organisms converted by geological processes.

Petroleum has advantages like affordability and easy transport, whereas risks include pollution and depletion of reserves. Coal formation arises from prehistoric plant matter undergoing transformations, with ranks of coal indicating quality. Nuclear reactors consist of crucial components, and serious nuclear accidents like Chernobyl and Three Mile Island underscore the risks of nuclear energy. Alternative energy sources offer sustainable options to reduce reliance on fossil fuels. Remediation aims to restore contaminant-affected areas.

The LD 50 denotes the lethal dose for 50% of a population, while various toxins like mutagens, teratogens, and carcinogens pose health risks. The threshold dose reflects the maximum concentration without measurable effects, while sulfur emerges as a principal environmental pollutant due to coal combustion. Mercury sources include coal burning, with volcanoes and earthquakes typically occurring at tectonic plate boundaries. The tragedy of the commons illustrates shared resource exploitation, highlighting resource management challenges. Forest fires vary in type with their impacts on ecosystems, and staple crops like rice, wheat, and corn dominate global food supplies. Monoculture practices often lead to various ecological concerns. Temperature inversions can trap pollutants, exacerbating air quality issues.

Transpiration is a fundamental water cycle process for plants, while the atmosphere consists of multiple layers, each serving distinct functions, including weather and protection from harmful radiation. Dioxins and PCBs signify hazardous chemical pollutants related to industrial activities. Public land usage varies with regulations in place for preservation and sustainable resource management. Understanding these concepts aids in addressing contemporary environmental challenges while promoting greater ecological awareness.

Ionizing radiation is defined as radiation with enough energy to dislodge electrons from atoms, creating ions. Examples of ionizing radiation include gamma rays, X-rays, and ultraviolet (UV) radiation, which can be capable of causing cancer.

High-quality energy is defined as organized and concentrated energy that can perform useful work, with fossil fuels and nuclear energy serving as prominent examples. In contrast, low-quality energy is characterized as disorganized and dispersed energy, like heat in the ocean or air, wind, and solar energy.

The first law of thermodynamics states that energy is neither created nor destroyed but can be converted from one form to another, which is often referred to as the law of conservation of energy. The second law of thermodynamics states that when energy changes form, some useful energy is invariably degraded into lower quality energy, typically in the form of heat.

Natural radioactive decay involves unstable radioactive isotopes releasing gamma rays, alpha particles, and beta particles, with radon being a common example. The half-life of a radioactive isotope is the time it takes for half the mass of that isotope to decay. It is often advised to store radioactive isotopes for approximately 10 half-lives to decay to a safe level.

Nuclear fission is defined as the splitting of the nuclei of isotopes when struck by neutrons, whereas nuclear fusion involves two isotopes of light elements, such as hydrogen, being forced together at high temperatures to form a heavier nucleus, like helium. Nuclear fusion is still considered expensive, with the break-even point not yet reached, but it occurs naturally in the Sun. An ore is defined as rock containing a high enough concentration of a mineral to be profitable to mine, while a mineral reserve refers to identified mineral deposits that are currently profitable to extract. The best solutions to an energy shortage include conservation, increased efficiency, and exploring alternative energy sources. Organic fertilizers are characterized by their slow-acting and long-lasting nature due to the time needed for organic remains to decompose. Surface mining offers advantages such as lower costs, the potential to remove more minerals, and being less hazardous to workers. Humus is the organic, dark material that remains after decomposition by microorganisms, while leaching refers to the removal of dissolved materials from soil by water moving downwards. Illuviation is the deposit of leached material in lower soil layers, specifically the B horizons. Loam, which is considered ideal agricultural soil, consists of optimal proportions of sand (40%), silt (40%), and clay (20%). Soil conservation methods like conservation tillage, crop rotation, contour plowing, and the use of organic fertilizers are essential in managing soil health. Soil salinization occurs in arid regions where water evaporates and leaves salts behind, with the Fertile Crescent serving as an example. Conservation is defined as using resources responsibly, while preservation involves setting aside areas and protecting them from human activities. Water logging is defined as the saturation of soil with water, which deprives plant roots of oxygen and causes them to rot. The hydrologic cycle comprises components such as evaporation, transpiration, runoff, condensation, precipitation, and infiltration. A watershed is defined as all the land that drains into a body of water, while an aquifer refers to underground layers of porous rock that allow water to move slowly. The cone of depression is the lowering of the water table around a pumping well, and saltwater intrusion describes the movement of saltwater into an aquifer due to over-pumping of groundwater near the coast. The El Nino Southern Oscillation (ENSO) is characterized by the see-sawing of air pressure over the South Pacific, famously resulting in trade winds weakening and warm water migrating toward South America during an El Nino year. This phenomenon causes diminished fisheries off South America, droughts in the western Pacific, increased precipitation in southwestern North America, and fewer Atlantic hurricanes. The associated effects disrupt food chains, leading to decreased upwelling and variable winters in the Northern U.S. In contrast, La Nina refers to a “normal” year characterized by consistent easterly trade winds and warm water concentrated in the western Pacific, resulting in upwelling off the West Coast of South America. Nitrogen fixation is a process involving the conversion of atmospheric nitrogen into ammonia by bacteria, making it usable by plants. Ammonification is when decomposers convert organic waste into ammonia, while nitrification is the process where ammonia is converted to nitrate ions (NO₃⁻). Assimilation occurs when inorganic nitrogen is converted into organic molecules such as DNA, amino acids, and proteins. Denitrification involves bacteria converting nitrate (NO₃⁻) and nitrite (NO₂⁻) back into nitrogen gas (N₂). The phosphorus cycle distinctly differs from the nitrogen cycle in that phosphorus does not exist as a gas; it is released through the weathering of phosphate rocks (PO₄³⁻) and operates more slowly without atmospheric involvement. As a major limiting nutrient in plant growth, phosphorus plays a critical role. In aquatic ecosystems, phosphorus sources include runoff from animal waste, fertilizers, and sewage discharge. Sustainability refers to the ability to meet current needs without compromising future generations' ability to meet theirs. Photosynthesis is the process through which plants convert CO₂ into complex carbohydrates (sugars), primarily glucose (C₆H₁₂O₆). Aerobic respiration is when oxygen-consuming producers, consumers, and decomposers break down complex organic compounds, reverting carbon back into CO₂. Carbon is stored primarily in carbonates (CO₃²⁻) and oceans, which serve as the largest reservoirs. In ecosystems, biotic refers to the living components while abiotic pertains to non-living factors. Producers or autotrophs are organisms that generate their own food, typically through photosynthesis or chemosynthesis. The trophic levels in a food web follow the order: producers, primary consumers, secondary consumers, and tertiary consumers. Energy flow in food webs follows the 10% rule whereby only 10% of usable energy is passed to the next trophic level due to energy loss as heat and unconsumed biomass. Succession denotes the gradual colonization of a habitat following an environmental disturbance, with primary succession referring to development in a lifeless area while secondary succession indicates life progression where soil remains. The climax community is the stable final set of organisms in an ecological succession. Symbiosis occurs when members of different species live closely together, encompassing mutualism (where both organisms benefit), commensalism (one benefits, the other is unaffected), and parasitism (one benefits at the host's expense). Biomes represent large distinct terrestrial regions characterized by similar climate, soil, plants, and animals. Carrying capacity is the maximum number of individuals that an area can sustain. R strategists typically reproduce early and have many small offspring, while K strategists reproduce later and care for fewer offspring. Positive feedback mechanisms promote further change, such as warmer environments prompting more snowmelt, while negative feedback works to counteract changes like increased ocean evaporation leading to more clouds and less sunlight reaching the ground. Natural selection fosters the survival of organisms with favorable adaptations, enhancing their reproductive success. Exotic or invasive species, which disrupt the ecosystem balance and thrive in new environments, serve as a significant ecological concern. The doubling time rule, derived from a growth rate percentage, estimates how long it will take for a population to double. Replacement level fertility refers to the number of births needed for a population to replace itself, averaging around 2.1 in developed nations and 2.7 in less developed ones. The world population sits at approximately 7.5 billion, with the U.S. population around 327 million as of the note's creation. The demographic transition model outlines four stages, from the preindustrial stage with high birth and death rates to a postindustrial state characterized by low rates. Key factors affecting population growth include the low status of women, with methods to decrease birth rates including family planning, contraception, and economic incentives. About 97.5% of Earth’s water is seawater, while only 2.5% is freshwater. Conservation methods include techniques like drip irrigation in agriculture, recycling in industry, and utilizing gray water or low-flow fixtures at home. Gray water refers to any wastewater from a home except toilet water at times, which can be used for irrigation. Water pollution is categorized into point source pollution (from specific locations) and non-point source pollution (spread across areas). Sewage treatment includes primary treatment, which removes particulate matter, and secondary treatment, where bacteria breaks down organic waste. Biological Oxygen Demand (BOD) measures the oxygen needed by aerobic decomposers, while eutrophication results from nitrogen and phosphorus excess, leading to algal blooms and decreased oxygen levels, ultimately causing hypoxia, which compromises aquatic life. Indicators like fecal coliform (Enterococcus bacteria) reflect sewage contamination, and chlorine is an essential disinfectant that may also produce harmful byproducts. Minamata disease arises from methylmercury poisoning, while CAFÉ standards establish fuel efficiency regulations for vehicles. Primary air pollutants originate from both human and natural activities, while secondary pollutants form from the reactions of primary pollutants. Specific pollutants such as particulate matter, nitrogen oxides, and sulfur oxides have defined sources and reduction strategies. Carbon dioxide and monoxide are recognized for their greenhouse effects and health impacts, while ozone is a significant secondary pollutant affecting respiratory health. Radon is a naturally occurring radioactive gas that poses health risks, and photochemical smog indicates chemical reactions facilitated by sunlight. Greenhouse gases are key contributors to global warming, and ozone depletion results from substances like CFCs, leading to increased UV exposure and health issues. The Love Canal incident reflects the environmental impact of industrial waste, while municipal solid waste primarily consists of paper in landfills. Sanitary landfill issues pertain to leachate and methane gas with various solutions provided. Incineration poses advantages and disadvantages, including waste volume reduction and toxic emissions. The best strategy for resolving waste issues emphasizes reducing waste generation at the source. True cost encompasses environmental side effects not captured in product pricing, while brownfields denote abandoned industrial sites. Keystone species greatly impact ecosystem stability, whereas indicator species signal environmental health. In natural ecosystems, pest control methods rely predominantly on intrinsic community dynamics. Major insecticide classifications include chlorinated hydrocarbons, organophosphates, and carbamates, each with pros and cons. Natural pest management approaches promote practices like genetic resistance in plants. Genetically modified organisms (GMOs) arise from altering existing organisms' genetic make-up to create desired traits. Electric generation methods harness steam from various energy sources to produce electricity, with petroleum deriving from ancient aquatic organisms converted by geological processes. Petroleum has advantages like affordability and easy transport, whereas risks include pollution and depletion of reserves. Coal formation arises from prehistoric plant matter undergoing transformations, with ranks of coal indicating quality. Nuclear reactors consist of crucial components, and serious nuclear accidents like Chernobyl and Three Mile Island underscore the risks of nuclear energy. Alternative energy sources offer sustainable options to reduce reliance on fossil fuels. Remediation aims to restore contaminant-affected areas. The LD 50 denotes the lethal dose for 50% of a population, while various toxins like mutagens, teratogens, and carcinogens pose health risks. The threshold dose reflects the maximum concentration without measurable effects, while sulfur emerges as a principal environmental pollutant due to coal combustion. Mercury sources include coal burning, with volcanoes and earthquakes typically occurring at tectonic plate boundaries. The tragedy of the commons illustrates shared resource exploitation, highlighting resource management challenges. Forest fires vary in type with their impacts on ecosystems, and staple crops like rice, wheat, and corn dominate global food supplies. Monoculture practices often lead to various ecological concerns. Temperature inversions can trap pollutants, exacerbating air quality issues. Transpiration is a fundamental water cycle process for plants, while the atmosphere consists of multiple layers, each serving distinct functions, including weather and protection from harmful radiation. Dioxins and PCBs signify hazardous chemical pollutants related to industrial activities. Public land usage varies with regulations in place for preservation and sustainable resource management. Understanding these concepts aids in addressing contemporary environmental challenges while promoting greater ecological awareness.

RESOURCES

https://quizlet.com/425241007/learn?funnelUUID=493d6fe6-cbc8-4d0f-937c-cc7cf58fe473