Presentation on theme: "Advanced Placement Environmental Science La Canada High School Dr. E"— Presentation transcript:
1Advanced Placement Environmental Science La Canada High School Dr. E Human Impact on the Atmosphere Chapters 18 and 19 Living in the Environment, 11th Edition, MillerAdvanced Placement Environmental ScienceLa Canada High SchoolDr. E
2Pollution Thorpe, Gary S. , M. S. , (2002) Pollution Thorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement ExamThe term “Smog” (smoke and fog) was first used in 1905 to describe sulfur dioxide emissionIn 1952, severe pollution took the lives of 5000 people in London“It isn’t pollution that’s harming the environment. It’s the impurities in our air and water that are doing it.” Former U.S. Vice President Dan Quayle97annual.html
3The Clean Air Act Congress found: • Most people now live in urban areas• Growth results in air pollution• Air pollution endangers living thingsIt decided:• Prevention and control at the source was appropriate• Such efforts are the responsibility of states and local authorities• Federal funds and leadership are essential for the development of effective programsThe Clean Air Act
4Clean Air Act Originally signed 1963 States controlled standards1970 – Uniform Standards by Federal Govt.Criteria PollutantsPrimary – Human health riskSecondary – Protect materials, crops, climate, visibility, personal comfort
5Clean Air Act 1990 version 1997 version Acid rain, urban smog, toxic air pollutants, ozone depletion, marketing pollution rights, VOC’s1997 versionReduced ambient ozone levelsCost $15 billion/year -> save 15,000 livesReduce bronchitis cases by 60,000 per yearReduce hospital respiratory admission 9000/year
6Clean Air ActPresident George W. Bush signed rules amending Clean Air Act that allowed power plants and other industries to increase pollution significantly without adopting control measures
7Appeals court blocks Bush clean air changes Appeals court blocks Bush clean air changesWednesday, December 24, 2003 Posted: 2:10 PM EST (1910 GMT)WASHINGTON (AP) -- A federal appeals court on Wednesday blocked new Bush administration changes to the Clean Air Act from going into effect the next day, in a challenge from state attorneys general and cities that argued they would harm the environment and public health.
8Clean Air Act http://www.epa.gov/air/oaq_caa.html Title I - Air Pollution Prevention and ControlPart A - Air Quality and Emission LimitationsPart B - Ozone Protection (replaced by Title VI)Part C - Prevention of Significant Deterioration of Air QualityPart D - Plan Requirements for Nonattainment AreasTitle II - Emission Standards for Moving SourcesPart A - Motor Vehicle Emission and Fuel StandardsPart B - Aircraft Emission StandardsPart C - Clean Fuel VehiclesTitle III - GeneralTitle IV - Acid Deposition ControlTitle V - PermitsTitle VI - Stratospheric Ozone Protection
11Major Sources of Primary Pollutants Stationary SourcesCombustion of fuels for power and heat – Power PlantsOther burning such as Wood & crop burning or forest firesIndustrial/ commercial processesSolvents and aerosolsMobile SourcesHighway: cars, trucks, buses and motorcyclesOff-highway: aircraft, boats, locomotives, farm equipment, RVs, construction machinery, and lawn mowers
12Source: http://www.epa.gov/air/oaqps/takingtoxics/p1.html#1 Scientists estimate that millions of tons of toxic pollutants are released into the air each year. Most air toxics originate from manmade sources, including both mobile sources (e.g., cars, buses, trucks) and stationary sources (e.g., factories, refineries, power plants). However, some are released in major amounts from natural sources such as forest fires. Routine emissions from stationary sources constitute almost one-half of all manmade air toxics emissions.
1354 million metric tons from mobile sources in 1990 There are two types of stationary sources that generate routine emissions of air toxics:"Major" sources are defined as sources that emit 10 tons per year of any of the listed toxic air pollutants, or 25 tons per year of a mixture of air toxics. Examples include chemical plants, steel mills, oil refineries, and hazardous waste incinerators. These sources may release air toxics from equipment leaks, when materials are transferred from one location to another, or during discharge through emissions stacks or vents. One key public health concern regarding major sources is the health effects on populations located downwind from them."Area" sources consist of smaller sources, each releasing smaller amounts of toxic pollutants into the air. Area sources are defined as sources that emit less than 10 tons per year of a single air toxic, or less than 25 tons per year of a mixture of air toxics. Examples include neighborhood dry cleaners and gas stations. Though emissions from individual area sources are often relatively small, collectively their emissions can be of concern—particularly where large numbers of sources are located in heavily populated areas.EPA’s published list of "source categories" now contains 175 categories of industrial and sources that emit one or more toxic air pollutants. For each of these source categories, EPA indicated whether the sources are considered to be "major" sources or "area" sources. The 1990 Clean Air Act Amendments direct EPA to set standards requiring all major sources of air toxics (and some area sources that are of particular concern) to significantly reduce their air toxics emissions.
14Human Impact on Atmosphere Burning Fossil FuelsUsing Nitrogen fertilizers and burning fossil fuelsRefining petroleum and burning fossil fuelsManufacturingAdds CO2 and O3 to troposphereGlobal WarmingAltering ClimatesProduces Acid RainReleases NO, NO2, N2O, and NH3 into troposphereProduces acid rainReleases SO2 into troposphereReleases toxic heavy metals (Pb, Cd, and As) into troposphereair/products.html
15Criteria Air Pollutants EPA uses six "criteria pollutants" as indicators of air qualityNitrogen Dioxide: NO2Ozone: ground level O3Carbon monoxide: COLead: PbParticulate Matter: PM10 (PM 2.5)Sulfur Dioxide: SO2Volatile Organic Compounds: (VOCs)EPA established for each concentrations above which adverse effects on health may occur
16Nitrogen Dioxide (NO2)Properties: reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in airEffects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growthSources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soilClass: Nitrogen oxides (NOx)EPA Standard: ppm
18Ozone (O3)Properties: colorless, unpleasant odor, major part of photochemical smogEffects: lung irritant, damages plants, rubber, fabric, eyes, 0.1 ppm can lower PSN by 50%,Sources: Created by sunlight acting on NOx and VOC , photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion productsClass: photochemical oxidants
19Ozone (O3)10,000 to 15,000 people in US admitted to hospitals each year due to ozone-related illnessChildren more susceptibleAirways narrowerMore time spent outdoors
20Mobile Source Emissions: Hydrocarbons – Precursors to Ozone
21Carbon Monoxide (CO)Properties: colorless, odorless, heavier than air, % of atmosphereEffects: binds tighter to Hb than O2, mental functions and visual acuity, even at low levelsSources: incomplete combustion of fossil fuels % from auto exhaustClass: carbon oxides (CO2, CO)EPA Standard: 9 ppm5.5 billion tons enter atmosphere/year
23Lead (Pb) Properties: grayish metal Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high]Sources: particulates, smelters, batteriesClass: toxic or heavy metalsEPA Standard: 1.5 ug/m32 million tons enter atmosphere/year
25Mobile Source Emissions: Fine Particulate Matter (PM2.5)
26Sulfur Dioxide (SO2) Properties: colorless gas with irritating odor Effects: produces acid rain (H2SO4), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicatorsSources: burning high sulfur coal or oil, smelting or metals, paper manufactureClass: sulfur oxidesEPA Standard: 0.3 ppm (annual mean)Combines with water and NH4 to increase soil fertility
27VOCs (Volatile Organic Compounds) Properties: organic compounds (hydrocarbons) that evaporate easily, usually aromaticEffects: eye and respiratory irritants; carcinogenic; liver, CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warmingSources: vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaningClass: HAPs (Hazardous Air Pollutants)MethaneBenzeneChlorofluorocarbons (CFCs), etc.Concentrations indoors up to 1000x outdoors600 million tons of CFCs
28Other Air Pollutants Carbon dioxide ChloroFluoroCarbons Formaldehyde BenzeneAsbestosManganeseDioxinsCadmiumOthers not yet fully characterized
29Formation & Intensity Factors Local climate (inversions, air pressure, temperature, humidity)Topography (hills and mountains)Population densityAmount of industryFuels used by population and industry for heating, manufacturing, transportation, powerWeather: rain, snow,windBuildings (slow wind speed)Mass transit usedEconomics
30Thermal Inversion Pollutants • surface heated by sun warmaircool air• surface heated by sun• warm air rises (incl. pollutants)• cools off, mixes with air of equaldensity & disperseswarm air (inversion layer)• surface cools rapidly (night)• a layer of warm air overlays surface• polluted surface air rises but cannotdisperse remains trapped
31Smog Forms ...when polluted air is stagnant (weather conditions, geographic location)Los Angeles, CA
32Primary Pollutants CO CO2 Secondary Pollutants SO2 NO NO2 SO3 Most hydrocarbonsHNO3H2SO4Most suspendedparticlesH2O2O3PANsSO42–MostNO3–andsaltsNaturalSourcesStationaryMobile
34Ultraviolet radiation SolarradiationPhotochemical SmogUltraviolet radiationNONitric oxideOAtomicoxygenO2MolecularoxygenNO2NitrogendioxideH2OWaterHydrocarbonsPANsPeroxyacylnitratesAldehydes(e.g., formaldehyde)O3OzoneHNO3Nitric acidP h o t o c h e m i c a l S m o g
36Why is indoor air quality important? 70 to 90% of time spent indoors, mostly at homeMany significant pollution sources in the home (e.g. gas cookers, paints and glues)Personal exposure to many common pollutants is driven by indoor exposureEspecially important for susceptible groups – e.g. the sick, old and very young
37ExposureTime spent in various environments in US and less-developed countries
38House of Commons Select Committee Enquiry on Indoor Air Pollution (1991) “[There is] evidence that 3 million people have asthma in the UK… and this is increasing by 5% per annum.”“Overall there appears to be a worryingly large number of health problems which could be connected with indoor pollution and which affect very large numbers of the population.”[The Committee recommends that the Government] “develop guidelines and codes of practice for indoor air quality in buildings which specifically identify exposure limits for an extended list of pollutants…”
39Sources of Indoor Air Pollutants Building materialsFurnitureFurnishings and fabricsGluesCleaning productsOther consumer productsCombustion appliances (cookers and heaters)Open firesTobacco smokingCookingHouse dust mites, bacteria and mouldsOutdoor air
40Important Indoor Air pollutants Nitrogen dioxideCarbon monoxideFormaldehydeVolatile Organic Compounds (VOCs)House dust mites (and other allergens, e.g. from pets)Environmental tobacco smokeFine particlesChlorinated organic compounds (e.g. pesticides)Asbestos and man-made mineral fibresRadon
41Health Effects Nitrogen dioxide Respiratory irritant Elevated risk of respiratory illness in children, perhaps resulting from increased susceptibility to respiratory infection; inconsistent evidence for effects in adultsConcentrations in kitchens can readily exceed WHO and EPA standards
42Health Effects Carbon monoxide An asphyxiant and toxicant Hazard of acute intoxication, mostly from malfunctioning fuel-burning appliances and inadequate or blocked fluesPossibility of chronic effects of long-term exposure to non- lethal concentrations, particularly amongst susceptible groups
43Health Effects Formaldehyde Sensory and respiratory irritant and sensitizerPossible increased risk of asthma and chronic bronchitis in children at higher exposure levelsIndividual differences in sensory and other transient responsesCaution over rising indoor concentrations
44Health Effects Volatile Organic Compounds (VOCs) Occur in complex and variable mixturesMain health effects relate to comfort and well-being, but benzene (and other VOCs) are carcinogenicConcern about possible role of VOCs in the aetiology of multiple chemical sensitivity; also implicated in sick building syndrome
45Health Effects House dust mites House dust mites produce Der p1 allergen, a potent sensitizerGood evidence of increased risk of sensitization with increasing allergen exposure, but this does not necessarily lead to asthmaSmall reductions in exposure will not necessarily lead to reduced incidence and/or symptomsIndoor humidity is important
46Health Effects Fungi and bacteria Dampness and mould-growth linked to self-reported respiratory conditions, but little convincing evidence for association between measured airborne fungi and respiratory diseaseInsufficient data to relate exposure to (non-pathogenic) bacteria to health effects in the indoor environment
47Health Effects Environmental tobacco smoke (ETS) Sudden infant death syndromeLower respiratory tract illnessMiddle ear diseaseAsthma12 million children exposed to secondhand smoke in homes
48Health Effects Fine particles Consistent evidence that exposure to small airborne particles (e.g. PM10) in ambient air can impact on human health; mechanisms uncertainChronic Obstructive Pulmonary Disease and Cardiovascular Disease patients and asthmatics probably at extra riskRelative importance of indoor sources is unknown
49Health Effects Radon Can cause lung cancer Estimated that 7,000 to 30,000 Americans die each year from radon-induced lung cancerOnly smoking causes more lung cancer deathsSmokers more at risk than non-smokers
50Radon Risk: Non-Smoker Radon Level(pCI/L)If 1000 people who did not smoke were exposed to this level over a lifetime.. About X would get lung cancerThis risk of cancer from radon exposure compares to …What to do:208Being killed in a violent crimeFix your home104310x risk of dying in a plane crash2Risk of drowning<1Risk of dying in a home fire1.3Average indoor radon level.4If you are a former smoker, your risk may be higher
51Radon Risk: Smoker If you are a former smoker, your risk may be lower Radon Level(pCI/L)If 1000 people who smoke were exposed to this level over a lifetime.. About X would get lung cancerThis risk of cancer from radon exposure compares to …What to do:Stop smoking and …20135100x risk of drowningFix your home1071100x risk of dying in a home fire857429100x risk of dying in a plane crash2152x the risk of dying in a car crash1.39Average indoor radon level.43If you are a former smoker, your risk may be lower
52Radon 55% of our exposure to radiation comes from radon colorless, tasteless, odorless gasformed from the decay of uraniumfound in nearly all soilslevels vary
53(From: http://www.epa.gov/iaq/radon/zonemap.html) Zone pCi/L>4<2
54Radon: How it Enters Buildings Cracks in solid floorsConstruction jointsCracks in wallsGaps in suspended floorsGaps around service pipesCavities inside wallsThe water supply
55Radon: Reducing the Risks Sealing cracks in floors and wallsSimple systems using pipes and fansMore information:Such systems are called "sub-slab depressurization," and do not require major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces.
56Sick Building Syndrome (SBS) Building Related Illness (BRI) vsBuilding Related Illness (BRI)
57Sick Building Syndrome A persistent set of symptoms in > 20% populationCauses(s) not known or recognizableComplaints/Symptoms relieved after exiting building
58Complaints/Symptoms Headaches Fatigue Reduced Mentation Irritability Eye, nose or throat irritationDry SkinNasal CongestionDifficulty BreathingNose BleedsNausea
59Building Related Illness Clinically Recognized DiseaseExposure to indoor air pollutantsRecognizable Causes
62Movement of Air Into / Out of Homes Amount of air available to dilute pollutantsimportant indicator of the likely contaminant concentrationIndoor air can mix with outside air by three mechanismsinfiltrationnatural ventilationforced ventilation
63Movement of Air Into / Out of Homes Infiltrationnatural air exchange that occurs between a building and its environment when the doors and windows are closedleakage through holes or openings in the building envelopepressure induceddue to pressure differentials inside and outside of the buildingespecially important with cracks and other openings in wall
64Movement of Air Into / Out of Homes InfiltrationTemperature induced (stack effect)driven by air movement through holes in floors, ceilingsin winter, warm air in a building wants to rise, exits through cracks in ceiling and draws in
65Movement of Air Into / Out of Homes Natural ventilationair exchange that occurs when windows or doors are opened to increase air circulationForced ventilationmechanical air handling systems used to induce air exchange using fans and blowersTrade-offscut infiltration to decrease heating and cooling costs vs. indoor air quality problems
66Movement of Air Into / Out of Homes Infiltration ratesInfluenced byhow fast wind is blowing, pressure differentialstemperature differential between inside and outside of houselocation of leaks in building envelope
73Average Temperature Over Past 900,000 Years Thousands of Years AgoAverage Surface Temperature (°C)900800700600500400300200100Present91011121314151617
74Temperature Change Over Past 22,000 Years Years AgoTemperature Change (°C)20,00010,0002,0001,000200100Now-5-4-3-2-112End oflast iceageAgriculture establishedAverage temperature over past10,000 years = 15°C (59°F)
75Average Temperature Over Past 130 Years Average Surface Temperature (°C)18601880190019201940196019802000202013.613.814.014.214.414.614.815.0
77Thousands of Years Before Present in the Atmosphere (ppm) Carbon dioxideTemperaturechangeEnd oflast ice age1601208040Thousands of Years Before Presentin the Atmosphere (ppm)Concentration of CO2180200220240260280300320340360380–10.0–7.5–5.0–2.5+2.5Variation of temperature (˚C)from current level
83MethaneCore samples taken from old ocean sediment layers have been used to trace back in time the climate changes that have occurred over the past tens of millions of yearsshort periods of only a few hundred years in the geological past when rapid increases of the Earth's temperature have occurred superimposed on top of the rise and fall of average temperatures over the longer term up to 15 degrees centigrade warmer than today.
84MethaneTemperatures then fell back to the long term trend, the whole rise and fall only lasting a few hundred years.The most likely cause of this rapid global warming over such a short period is the release of methane into the atmosphere.Methane is 60 times more powerful than CO2 as a greenhouse gasMethane was released due to breakdown of material associated with permafrost
86Change in Temperature (ºC) Year185018751900192519501975200020252050207521000.51.01.52.02.53.03.54.04.55.05.56.0Change in Temperature (ºC)Predictions of Future Warming?
87Top Greenhouse Gas Emitters 19.1 % - United States9.9% - China5.1% - Japan4.3% - Brazil3.8 % - Germany3.7% - Japan2.4% - United Kingdom1.9% - Indonesia1.7% - Italy
88What impacts have occurred and are predicted to occur from global warming?
89Atmosphere Impacts from Global Warming? WeatherOcean currentsSea levelWater resourcesBiodiversityForestsHuman healthAgricultureHuman demographics
90Sea Level and Coastal Areas Increased deaths from heat and diseaseDisruption of food and water suppliesSpread of tropical diseases to temperate areasIncreased respiratory diseaseIncreased water pollution from coastal floodingHuman HealthRising sea levelsFlooding of low-lying islands and coastal citiesFlooding of coastal estuaries, wetlands, and coral reefsBeach erosionDisruption of coastal fisheriesContamination of coastal aquifiers with salt waterSea Level and Coastal AreasChanges in forest composition and locationsDisappearance of some forestsIncreased fires from dryingLoss of wildlife habitat and speciesForestsChanges in water supplyDecreased water qualityIncreased droughtIncreased floodingWater ResourcesShifts in food-growing areasChanges in crop yieldsIncreased irrigation demandsIncreased pests, crop diseases, and weeds in warmer areasAgricultureExtinction of some plant and animal speciesLoss of habitatsDisruption of aquatic lifeBiodiversityProlonged heat waves and droughtsMore intense hurricanes, typhoons, tornadoes, and violent stormsWeather ExtremesIncreased deathsMore environmental refugeesIncreased migrationHuman Population
91Direct manifestations Heat waves and periods of unusually warm weatherSea level rise and coastal floodingGlaciers meltingArctic and Antarctic warming with ice shelves breaking upIncrease severity of weatherZooplankton are dying in the Pacific Ocean
92Heat wave kills 30, no relief in sight July 27, 1999
93Monster iceberg breaks off Antarctic ice shelf May 10, 2002
94Cold water melting from Antarctica's ice cap and GreenlandCold water melting fromAntarctica's ice cap andicebergs falls to the ocean floorand surges northward, affectingworldwide circulation.Antarctica
95present sea level (meters) Today’s sea levelYears before presentPresent250,000200,000150,000100,00050,000–130–426present sea level (meters)Height above or belowHeight below presentsea level (feet)
96If all the ice on Greenland melted, world sea levels would rise about six metres (20 feet) If all the ice on the Antarctic continent melted, sea levels would rise over 70 metres (230 feet) This is unlikely to happen, but small increases will continue.
101Possible Consequences Spreading diseaseEarlier spring arrivalPlant and animal range shifts and population declinesCoral reef bleachingDownpours, heavy snowfalls, and floodingDroughts and fires
102Global warming may harm human health November 16, 1998Climatic changes relatedto global warming couldfoster dangerous outbreaksof cholera, dengue feverand malaria, …
103Study: Global warming spurs migrations Thursday, January 2, 2003Rising global temperatures that have lured plants into early bloom and birds to nest earlier in the spring are altering the ranges and behavior of hundreds of plant and animal species worldwide, two studies conclude.
104Report: Coral bleaching hits record level May 19, 1999Global warming hasbeen linked to anunprecedented episodeof coral bleachingin 1998, …
105Vicious cycle: Global warming feeds fire potential November 2, 2000Global warming may greatly accelerate the firecycle in the desert ecosystem of North America,according to a study published today in the journalNature.Elevated carbon dioxide levels, the result ofincreased fossil fuel burning, can alter the delicatebalance of grasses in desert areas, the report notes.This finding may have major implications for thebiodiversity and health of desert ecosystems in thewestern United States."This could be a real problem for land managers,"said Stan Smith, a professor of biology at theUniversity of Nevada in Las Vegas and leadauthor of the study.
110Understanding Ozone http://royal. okanagan. bc Discovered in 1839 by German scientist Christian Friedrich SchonbeinPale blue, unstable molecule made of three oxygen atomsVital to life in the stratosphereHarmful to plants and humans in the troposphereConcentration: stratosphere up to 15 ppm at about 25 kmFormed when atomic oxygen (O) from higher parts of the atmosphere collides with molecular oxygen (O2) in the stratosphereUV radiation splits the ozone back to O and O2 and it can form another ozone molecule
113The Ozone HoleFirst discovered in 1985: observations from Antarctica extend back into 1950’s.Characterized as a rapid depletion of ozone over Antarctica during spring.Ozone hole season, Spring (August – October)Ozone hole located over mainly over Antarctica.Ozone hole recovers by late DecemberOzone hole caused by human chemicals (CFC’s)Ozone hole not present in early 1970’sObservations over Antarctica data back to the 1950’s. The discovery of the ozone hole occurred in It turns out that the research group measuring ozone had seen a sharp decline in ozone levels during October over Antarctica (see next overhead), but didn’t report it immediately because they worried that their instrument might be faulty. Finally, after a few years of testing, they published a paper documenting this rapid decline of ozone levels. However, at the time, there was no explanation for why ozone was declining.During that same time period, NASA was also observing ozone levels globally. However, they didn’t expect to see signs of ozone depletion over Antarctica, and consequently, ‘missed’ the ozone hole due to a computer glitch. When they realized their mistake, and fixed up the computer problem, they also saw the clear signs of an emerging hole in the ozone layer.The ozone hole is characterized by a rapid depletion of ozone over Antarctica during the springtime.The science of the ozone hole was well understood by the early 1990s.
115(Key Learning Figure)Many students (and the public) have the perception that the ozone hole (and ozone in general) is getting much worse. This is likely due to press reports that usually say, ‘the ozone hole reached it’s largest size…’ The reality is that in the last decade, the size and severity of the ozone hole have stayed about the same, compared to rapid changes seen in the middle 1980’s.Year to year variations in the depth and severity of the ozone hole is really a function of the atmospheric weather conditions (I.e. the colder the winter, the more greater the ozone loss). In addition, the ozone hole is about as bad as it can get. Between km, all the ozone is essentially destroyed during spring over Antarctica, so it couldn’t get much worse. Thus, we don’t expect the size and depth of the ozone hole to change dramatically in the future. Rather, it is expected that the size of the ozone hole is about as big as it’s going to get, and with time (10 or more years) and reduced chlorine levels, we should start to see the size of the ozone hole get smaller.Thus, this graphic is intended to illustrate how in the 80’s, the size of the ozone hole increased rapidly, while in the 90’s and 2000, things stabilized.
118Ozone hole stabilizes October 17, 2001 WASHINGTON (CNN) A hole in the Earth's protective ozone layeris about the same size as in the past threeyears, according to scientists at the NationalOceanic and Atmospheric Administration,who predict it will hold steady in the nearfuture.Satellite data show the hole over Antarctica,which allows more harmful solar radiation toreach the Earth, peaked this year at about 10million square miles (26 million square km),roughly the size of North America.
120History of Ozone Depletion CFCs developed in 40’s and 50’sRefrigerants, propellants, fire retardants1970’s CFCs detected in atmosphere.Many of these have long atmospheric lifetimes (10’s to 100’s of years)1974 Rowland and Molina propose that CFC’s can destroy ozone in the stratosphere.CFCs broken apart by UV radiation forming chlorine which can destroy ozone quickly:O3 +Cl ClO+ O2 (Catalytic Reaction)ClO+O Cl+O2(advanced)CFC’s are a class of chemicals that were developed in the 40 and 50s for many valuable applications including refrigerants, propellants (for spray cans) and fire retardants. One of the most remarkable and extremely valuable characterizes of CFC’s is that they do not react anything. Therefore, if you have some type of fire, you can safely use CFC’s to extinguish the fire, not worrying if your fire retardant is going to enhance the fire.This characteristics of CFC’s also means that many CFC’s remain in the atmosphere for many years (10’s to 100’s). They have long atmospheric lifetimes. Therefore, if you release a CFC molecule into the atmosphere, it may bounce around in the atmosphere for many many years.In 1974, two scientist (Rowland and Molina; who later received the Nobel Prize in chemistry) suggested that because CFC’s are around for a long time, they may eventually reach the upper atmosphere, where they can be broken apart by the sun. CFC’s contain chlorine, a chemical that can rapidly destroy ozone under certain conditions, and in some cases, a single chlorine atom may destroy thousands of ozone molecules through a self replicating cycles (catalytic reaction).The catalytic cycle is self replicating…ozone gets converted by chlorine, producing ClO and more oxygen. The ClO then reacts with a free oxygen atom, thereby producing another Cl atom. The cycle can then continue again.
121Chlorofluorocarbons or CFCs First produced by General Motors Corporation in 1928, CFCs were created as a replacement to the toxic refrigerant ammoniaCFCs have also been used as a propellant in spray cans, cleaner for electronics, sterilant for hospital equipment, and to produce the bubbles in Styrofoam
122CFCs are cheap to produce and very stable compounds, lasting up to 200 years in the atmosphere Many countries have recently passed laws banning nonessential use of these chemicals.Nevertheless, by 1988 some 320,000 metric tons of CFCs were used worldwide.
125Action of CFCsCFCs created at the Earth's surface drift slowly upward to the stratosphere where UV radiation from the sun causes their decomposition and the release of chlorineChlorine in turn attacks the molecules of ozone converting them into oxygen moleculesCl + O3 »»» ClO + O2ClO + O »»» Cl + O2
126Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breakingoff a chlorine atom and leavingCFCl2.SunClClOnce free, the chlorine atom is offto attack another ozone moleculeand begin the cycle again.CClFUV radiationClClOOA free oxygen atom pullsthe oxygen atom offthe chlorine monoxidemolecule to form O2.The chlorine atom attacksan ozone (O3) molecule, pulling an oxygen atomoff it and leavingan oxygenmolecule (O2).ClClOOOOOThe chlorineatom and theoxygen atom jointo form a chlorinemonoxide molecule (ClO)ClOOO
128A single chlorine atom removes about 100,000 ozone molecules before it is taken out of operation by other substances
129Low and Middle Latitudes Current measurements indicate that the amount of ozone in the stratosphere of the low and middle latitudes has decreased by about 3% with estimates that it will decrease by10% by 2025
131Harmful effects of UV radiation. Skin cancer (ultraviolet radiation can destroy acids in DNA)Cataracts and sun burningSuppression of immune systemsAdverse impact on crops and animalsReduction in the growth of ocean phytoplanktonCooling of the Earth's stratosphere and possibly some surface climatic effectDegradation of paints and plastic material
134ConclusionOzone Depletion Exists and effects certain areas of the Earth more than othersCurrently, one in five North Americans and one in two Australians will develop some form of skin cancer in their lifetimeWith a sustained 10% decrease in stratospheric ozone, an additional 300,000 non-melanoma and 4,500 melanoma skin cancers could be expected world-wide, according to UNEP estimates.
137Measuring Acid Rain Acid rain is measured using a "pH" scale. The lower a substance's pH, the more acidic it is.Pure water has a pH of 7.0.Normal rain is slightly acidic and has a pH of about 5.6Any rainfall has a pH value less than 5.6 is defined as acid rainAs of the year 2000, the most acidic rain falling in the US has a pH of about 4.3.
138Two Forms… Wet Refers to acid rain, fog, sleet, cloud vapor and snow. DryRefers to acidic gases and particles.
139Compounds Two main contributers to acid deposition: Sulfur Dioxide (SO2)Nitrogen Oxides (NOx)* 66% of all sulfur dioxides and 25% of all nitrogen oxides comes from electric power generation that produces energy by burning fossil fuels.
140When gas pollutants e.g. sulphur dioxide, nitrogen dioxide dissolve in rain water, various acids are formed.CO2 + H2O H2CO3 (carbonic acid)SO2 + H2O H2SO3 (sulphorous acid)NO2 + H2O HNO2 (nitrous acid) HNO3 (nitric acid)
141Causes of Acid RainSulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain.In the US, About 2/3 of all SO2 and 1/4 of all NOx comes from electric power generation that relies on burning fossil fuels like coal.
142sulfuric acid nitric acid indirect health effects Acidic PrecipitationPrimary PollutantsSO2NO2Secondary PollutantsH2SO4 HNO2sulfuric acid nitric acidacidic precipitationvegetationdirect toxicityindirect health effectswaterFossil fuelsPower plantsIndustrial emissionsAuto emissionssoilsleaching of mineralssedimentsleaching aluminum
143Several processes can result in the formation of acid deposition Several processes can result in the formation of acid deposition. Nitrogen oxides (NOx) and sulfur dioxide (SO2) released into the atmosphere from a variety of sources call fall to the ground simply as dry deposition. This dry deposition can then be converted into acids when these deposited chemicals meet water. Most wet acid deposition forms when nitrogen oxides (NOx) and sulfur dioxide (SO2) are converted to nitric acid (HNO3) and sulfuric acid (H2SO4) through oxidation and dissolution. Wet deposition can also form when ammonia gas (NH3) from natural sources is converted into ammonium (NH4).
144Acidic Precipitation Wind Transformation to sulfuric acid (H2SO4) and nitric acid (HNO3)Windborne ammonia gasand particles of cultivated soilpartially neutralize acids andform dry sulfate and nitrate saltsWet acid deposition(droplets of H2SO4 andHNO3 dissolved in rainand snow)Dry aciddeposition(sulfur dioxidegas and particlesof sulfate andnitrate salts)Sulfur dioxide (SO2)and NONitric oxide (NO)Acid fogFarmLakes indeep soilhigh in limestoneare bufferedOceanLakes in shallowsoil low inlimestonebecomeacidic
148“Wet” Acid RainAcidic water flows over and through the ground, it affects a variety of plants and animals.
149“Dry” Acid Rain Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition.The wind blows these acidic particles and gases onto buildings, cars, homes, and trees.
150Increased AcidityDry deposited gases and particles can also be washed from trees and other surfaces by rainstorms.The runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone.
151Effects of Acid RainThe strength of the effects depend on many factorsHow acidic the water isThe chemistry and buffering capacity of the soils involvedThe types of fish, trees, and other living things that rely on the water
152Effects of Acid RainHas a variety of effects, including damage to forests and soils, fish and other living things, materials, and human health.Also reduces how far and how clearly we can see through the air, an effect called visibility reduction.Effects of acid rain are most clearly seen in the aquatic environmentsMost lakes and streams have a pH between 6 and 8
153Buffering CapacityAcid rain primarily affects sensitive bodies of water, which are located in watersheds whose soils have a limited "buffering capacity“Lakes and streams become acidic when the water itself and its surrounding soil cannot buffer the acid rain enough to neutralize it.
154In areas where buffering capacity is low, acid rain also releases aluminum from soils into lakes and streams; aluminum is highly toxic to many species of aquatic organisms.
156Effects on WildlifeGenerally, the young of most species are more sensitive to environmental conditions than adults.At pH 5, most fish eggs cannot hatch.At lower pH levels, some adult fish die.Some acid lakes have no fish.
157Effects on WildlifeBoth low pH and increased aluminum levels are directly toxic to fish.In addition, low pH and increased aluminum levels cause chronic stress that may not kill individual fish, but leads to lower body weight and smaller size and makes fish less able to compete for food and habitat.
158Acid Rain and Forests Acid rain does not usually kill trees directly. Instead, it is more likely to weaken trees by damaging their leaves, limiting the nutrients available to them, or exposing them to toxic substances slowly released from the soil.
161NutrientsAcidic water dissolves the nutrients and helpful minerals in the soil and then washes them away before trees and other plants can use them to grow.Acid rain also causes the release of substances that are toxic to trees and plants, such as aluminum, into the soil.
164Specific Air Pollution Treatment Technology TraditionalMove factory to remote locationBuild taller smokestack so wind blows pollution elsewhereNewBiofiltration : vapors pumped through soil where microbes degradeHigh-energy destruction: high-voltage electricityMembrane separation: diffusion of organic vapors through membraneOxidation: High temperature combustor
172Sulfur Dioxide Control Advanced Flue Gas Desulfurization Demonstration Project|Objective: To reduce SO2 emissions by 95% or more at approximately one-half the cost of conventional scrubbing technology, significantly reduce space requirements, and create no new waste streams.Technology/Project Description: Pure Air built a single SO2 absorber for a 528-MWe power plant. Although the largest capacity absorber module of its time in the United States, space requirements were modest because no spare or backup absorber modules were required. The absorber performed three functions in a single vessel: prequenching, absorbing, and oxidation of sludge to gypsum. Additionally, the absorber was of a co-current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to that in conventional scrubbers. These features all combined to yield a state-of-the-art SO2 absorber that was more compact and less expensive than contemporary conventional scrubbers.Other technical features included the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combined the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum.Pure Air also demonstrated a unique gypsum agglomeration process, PowerChip®, to significantly enhance handling characteristics of adsorbed flue gas desulfurization AFGD-derived gypsum.
174Source: NATIONAL AIR POLLUTANT EMISSION TRENDS, United States Environmental Protection Agency Office of Air Quality Planning and Standards EPA-454/RMarch 2000
175Comparison of 1970 and 1999 Emissions Source: Latest Findings on National Air Quality: 1999 Status and Trends EPA EPA-454/FSince the 1970 Clean Air Act was signed into law, emissions of each of the sixpollutants decreased, with the exception of NOx . Between 1970 and 1999,emissions of NOx increased 17 percent. The majority of this increase can beattributed to heavy-duty diesel vehicles and coal-fired power plants. EPA hasmajor initiatives to reduce emissions of NOx considerably from these sources.Emissions of NOx contribute to the formation of ground-level ozone (smog),acid rain, and other environmental problems, even after being carried by thewind hundreds of miles from their original source.
177Between 1970 and 1999, U.S. population increased 33 percent, vehicle miles traveled increased 140 percent, and gross domestic product increased 147 percent. At the same time, total emissions of the six principal air pollutants decreased 31 percent.
178EPA tracks trends in air quality based on actual measurements of pollutant concentrations in the ambient (outside) air at monitoringsites across the country. Monitoring stations are operated by state,tribal, and local government agencies as well as some federalagencies, including EPA. Trends are derived by averaging directmeasurements from these monitoring stations on a yearly basis. Thechart at above shows that the air quality based on concentrations ofthe principal pollutants has improved nationally over the last 20years (1980–1999). The most notable improvements are seen for Pb,CO, and SO2 with 94-, 57- and 50-percent reductions, respectively.
179Number of People Living in Counties with Air Quality Concentrations Above the Level of the National Ambient Air Quality Standards (NAAQS) in 1999Despite great progress in air quality improvement, approximately 62 million people nationwide still lived in counties with pollution levels above the national air quality standards in This number does not take into consideration the 8-hour ozone standard.Blue bars represent 8-hour standard for ozone.
180Trends in Sulfur Dioxide Emissions Following Implementation of Phase I of the Acid Rain Program: Total State-level Utility SO2 (1980, 1990, 1999)This set of maps illustrates the geographic and temporal trends in state-level utility sulfur dioxide (SO2) emissions before and during implementation of Phase I of the Acid Rain Program. The maps illustrate total state-level utility SO2 emissions in 1980, 1990, and 1999.Total sulfur dioxide emissions were significantly reduced during Phase I of the Acid Rain Program. In the first five years of the program, Phase I sources reduced SO2 emissions by more than 50% from 1980 levels; total utility SO2 emissions (Phase I and II sources) were reduced almost 30% nationwide. Although most SO2 emissions occur in the Midwestern U.S., it is important to note that over time, this same region has also seen the most significant decrease in SO2 emissions in the country. The highest SO2 emitting states in 1980 (Ohio, Indiana, and Pennsylvania), have achieved an average reduction of about 40%, from 1980 levels.Acid rain causes acidification of lakes and streams and contributes to damage of trees at high elevations (for example, red spruce trees above 2,000 feet) and many sensitive forest soils. In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable buildings, statues,and sculptures that are part of our nation's cultural heritage. Prior to falling to the earth, SO2 and NOx gases and their particulate matter derivatives, sulfates and nitrates, contribute to visibility degradation and harm public health.
181Fifty Years of Air Pollution Figures are in millions of metric tons per year
182Mobile Sources: The Last Ten Years VOCs CO NOx PM10 SOx LeadMobile Sources: The Last Ten Years-3%-8%-10%-24%-29%Percent reductions shown are based on estimates of tons/year from mobile sources over the time period-85%
183Who is Affected by Air Pollution? 63Over 74 million people are subjected to high levels of at least one of these pollutantsWho is Affected by Air Pollution?2219951Ozone CO NO PM10 SO2 LeadMillions of people living in counties with air quality that exceeds each NAAQS (1990 data)
184Milestones in the Control of Automotive Emissions Autos linked to air pollutionOriginal CAA, PCV valvesHC & CO exhaust controlsCAA amendments, EPA formedEvaporative controlsFirst I/M ProgramNOx exhaust controlsFirst catalytic convertersNew cars meet statutory limitsVolatility limits on gasolineNew CAA AmendmentsMilestones in the Control of Automotive Emissions
1851987 Montreal Protocol: CFC emissions should be reduced by 50% by the year 2000 (they had been increasing 3% per year.)1990 London amendments: production of CFCs, CCl4, and halons should cease entirely by 2000.1992 Copenhagen agreements: phase-out accelerated to 1996.
186What is the Kyoto Protocol? How did we get to Kyoto?What are the goals of Kyoto?Is Kyoto enough?
187Steps to Kyoto1985 International Council of Scientific Unions (Prof. Bert Bolin)“Many important economic and social decisions are being made today on long term projects, all based on the assumption that past climatic data, without modification, are a reliable guide to the future. This is no longer a good assumption”
188Steps to Kyoto 1988 - Toronto - creation of IPCC warmest summer to date, international meeting in TorontoIntergovernmental Panel on Climate Change formedFirst report (FAR)overview of the current science of climate change
189IPCC IPCC headed by Prof. Bert Bolin 3 working groupsClimate ScienceClimate ImpactsResponse StrategiesFAR used in Earth Summit meeting in Rio - United Nations Framework Convention on Climate Change
190IPCC1995 IPCC Second Assessment Report (SAR) completed, published in 1996WG I Climate ScienceWG II Impact, Adaptation and MitigationWG III Economic and Social Dimensions“The balance of evidence suggests a discernible human influence on global climate”
191IPCC 1997 Kyoto meeting - binding targets set culmination of a series of meetings since Rio (1992)2001 Bonn - rescuing Kyoto2001 IPCC Third Assessment Report (TAR)WG I Climate ScienceWG II Vulnerabilities, Impacts and AdaptationWG III Mitigation
192IPCCTAR (2001)“There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” (WG I)Global losses in weather related natural disasters have increased ten-fold from the 1960s to the 1990s, and that a portion of this increase must be due to increases in frequency and intensity of some extreme events. (WG II)“most of the opportunities to reduce emissions will come from energy efficiency gains and in reducing release of greenhouse gases from industry” (WG III)
193Goals of Kyoto Protocol Reduction of greenhouse gases to below 1990 levels:5.2% world wide reduction on average by6% for Canada byWhen sufficient countries ratify the Protocol (at least 55 countries comprising at least 55% of emissions), Protocol comes into effectUSA - 25% of emissions
195Fossil-Fuel CO2 Emissions (million metric tonnes C) Annex B CountriesNon Annex B CountriesFossil-Fuel CO2 Emissions (million metric tonnes C)Bunkers (million metric tonnes C)19903851782126411991375188230619923663922291431993361023414819943607248750199536249526075219963674270458199736969727756119983690100275662Source: Gregg Marland and Tom Boden (CDIAC, Oak Ridge National Laboratory).
196Greenhouse Effect - Conclusion Since 1700, humans have directly or indirectly caused the concentration of the major greenhouse gases to increaseScientists predict that this increase may enhance the greenhouse effect making the planet warmer by 0.3 to 0.6 degrees Celsius
197Cost of Regular Gasoline $3.80 – Great Britain$3.80 – The Netherlands$3.74 – Italy$3.69 – Belgium$3.62 – France$3.57 – Germany$3.20 – Japan$1.39 – United Statesin U.S. dollars as of October 13, 1997
198History of Global Warming 1904: Swedish scientist Svante Arrhenius was, according to NASA, "the first person to investigate the effect that doubling atmospheric carbon dioxide would have on global climate."
199History of Global Warming Arrhenius began studying rapid increases in anthropogenic – carbon emissions, determining that "the slight percentage of carbonic acid in the atmosphere may, by the advances of industry, be changed to a noticeable degree in the course of a few centuries."
200History of Global Warming The unique research of Arrhenius suggested that this increase could be beneficial, making Earth's climates "more equable" and stimulating plant growth and food production. Until about 1960, most scientists thought it implausible that humans could actually affect average global temperatures.
201History of Global Warming 1950s: Geophysicist Roger Revelle, with the help of Hans Suess, demonstrated that carbon dioxide levels in the air had increased as a result of the use of fossil fuels.
202History of Global Warming 1965: Serving on the President's Science Advisory Committee Panel on Environmental Pollution in 1965, Roger Revelle helped publish the first high-level government mention of global warming. The book-length report identified many of the environmental troubles the nation faced, and mentioned in a "subpanel report" the potential for global warming by carbon dioxide.
203History of Global Warming 1977: "In 1977 the nonpartisan National Academy of Sciences issued a study called Energy and Climate, which carefully suggested that the possibility of global warming 'should lead neither to panic nor to complacency.'
204History of Global Warming Rather, the study continued, it should 'engender a lively sense of urgency in getting on with the work of illuminating the issues that have been identified and resolving the scientific uncertainties that remain.'
205History of Global Warming As is typical with National Academy studies, the primary recommendation was for more research." — From "Breaking the Global-Warming Gridlock" by Daniel Sarewitz and Roger Pielke Jr., THE ATLANTIC, July 2000
206History of Global Warming Roger Revelle chaired the National Academy Panel, which found that about forty percent of the anthropogenic carbon dioxide has remained in the atmosphere, two-thirds from fossil fuel and one-third from the clearing of forests. It is now known that carbon dioxide is one of the primary greenhouse gases that contributes to global warming and remains in the atmosphere for a century.
207History of Global Warming 1980s: Representative Al Gore (D-TN), who had been a student of Revelle's, co-sponsored the first Congressional hearings to study the implications of global warming and to encourage the development of environmental technologies to combat global warming.
208History of Global Warming 1982: Roger Revelle published a widely-read article in SCIENTIFIC AMERICAN addressing the rise in global sea level and the "relative role played by the melting of glaciers and ice sheets versus the thermal expansion of the warming surface waters."
209History of Global Warming 1983: The Environmental Protection Agency released a report detailing some of the possible threats of the anthropogenic emission of carbon dioxide.
210History of Global Warming 1988: NASA climate scientist James Hansen and his team reported to Congress on global warming, explaining, "the greenhouse warming should be clearly identifiable in the 1990s" and that "the temperature changes are sufficiently large to have major impacts on people and other parts of the biosphere, as shown by computed changes in the frequency of extreme events and comparison with previous climate trends."
211History of Global Warming With the increased awareness of global warming issues, the Intergovernmental Panel on Climate Change (IPCC) was established by the World Meteorological Organization and the United Nations Environment Programme to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. The IPCC was the first international effort of this scale to address environmental issues.
212History of Global Warming 1990: Congress passed and President George Bush signed Public Law "The Global Change Research Act of The purpose of the legislation was "…to require the establishment of a United States Global Change Research Program aimed at understanding and responding to global change, including the cumulative effects of human activities and natural processes on the environment, to promote discussions towards international protocols in global change research, and for other purposes."
213History of Global Warming As part of the Act, the Global Change Research Information Office (GCRIO) was established "to disseminate to foreign governments, businesses, and institutions, as well as citizens of foreign countries, scientific research information available in the United States which would be useful in preventing, mitigating, or adapting to the effects of global change. The office began formal operation in 1993.
214History of Global Warming 1992: In June of 1992, over 100 government leaders, representatives from 170 countries, and some 30,000 participants met in Rio de Janeiro at the U.N. Conference on Environment and Development (UNCED or the "Earth Summit").
215History of Global Warming There, an international assembly formally recognized the need to integrate economic development and environmental protection into the goal of sustainable development.
216History of Global Warming 1997: In December, 1997, more than 160 nations met in Kyoto, Japan, to negotiate binding limitations on greenhouse gases for the developed nations, pursuant to the objectives of the Framework Convention on Climate Change of 1992.
217History of Global Warming The outcome of the meeting was the Kyoto Protocol, in which the developed nations agreed to limit their greenhouse gas emissions, relative to the levels emitted in The United States agreed to reduce emissions from 1990 levels by 7 percent during the period 2008 to 2012.
218History of Global Warming 1997: In December, 1997, more than 160 nations met in Kyoto, Japan, to negotiate binding limitations on greenhouse gases for the developed nations, pursuant to the objectives of the Framework Convention on Climate Change of 1992.
219History of Global Warming The outcome of the meeting was the Kyoto Protocol, in which the developed nations agreed to limit their greenhouse gas emissions, relative to the levels emitted in 1990.The United States agreed to reduce emissions from 1990 levels by 7 percent during the period 2008 to 2012.
220History of Global Warming Also that year, the United States Senate unanimously passed the Hagel-Byrd Resolution notifying the Clinton Administration that the Senate would not ratify any treaty that would (a) impose mandatory greenhouse gas emissions reductions for the United States without also imposing such reductions for developing nations, or (b) result in serious harm to our economy.
221History of Global Warming 2001: The IPCC released its third assessment report, concluding on the basis of "new and stronger evidence that most of the observed warming over the last 50 years is attributable to human activities." They also observed that "the globally averaged surface temperature is projected to increase by 1.4 to 5.8 degrees Celsius over the period 1990 to 2100."
222History of Global Warming The same year, President George W. Bush announced that the United States would not ratify the Kyoto Protocol. The Protocol is now in limbo until one of the two crucial holdouts — Russia or the United States — will ratify the treaty.
223History of Global Warming 2003: Senator John McCain (R-AZ) and Senator Joseph Lieberman (D-CT) co-sponsored a proposal for mandatory caps on "greenhouse gas" emissions from utilities and other industries.
224History of Global Warming Although the proposal was rejected in the Senate by a margin of 55 to 43, it was the Senators' first attempt to garner Senate attention for the issue of global warming, and McCain and Lieberman were encouraged by the support for the measure.