Human Impact on the Atmosphere. Pollution Thorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement Exam

Human Impact on the Human Impact on the AtmosphereAtmosphere

PollutionPollution Thorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement ExamThorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement Exam

• The term “Smog” (smoke and fog) was first used The term “Smog” (smoke and fog) was first used in 1905 to describe sulfur dioxide emissionin 1905 to describe sulfur dioxide emission

• In 1952, severe pollution took the lives of 5000 In 1952, severe pollution took the lives of 5000 people in London people in London

• ““It isn’t pollution that’s harming the It isn’t pollution that’s harming the environment. It’s the impurities in our air and environment. It’s the impurities in our air and water that are doing it.” water that are doing it.” FormerFormer U.S. U.S. Vice President Dan QuayleVice President Dan Quayle

www.aqmd.gov/pubinfo/ 97annual.html

http://www.aqmd.gov/pubinfo/97annual.html

TheTheCleaClea

nnAirAirActAct

Congress found:

• Most people now live in urban areas

• Growth results in air pollution

• Air pollution endangers living things

It 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 programs

Clean Air ActClean Air Act

• Originally signed 1963– States controlled standards

• 1970 – Uniform Standards by Federal Govt.– Criteria Pollutants

• Primary – Human health risk

• Secondary – Protect materials, crops, climate, visibility, personal comfort


• 1990 version – Acid rain, urban smog, toxic air pollutants, ozone

depletion, marketing pollution rights, VOC’s

• 1997 version– Reduced ambient ozone levels– Cost $15 billion/year -> save 15,000 lives – Reduce bronchitis cases by 60,000 per year– Reduce hospital respiratory admission 9000/year


President George W. Bush signed rules amending Clean Air Act that allowed power

plants and other industries to increase pollution significantly without adopting

control measures

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.

Appeals court blocks Bush clean air changesWednesday, December 24, 2003 Posted: 2:10 PM EST (1910 GMT)

http://www.cnn.com/2003/LAW/12/24/bush.clean.air.ap/index.html

http://www.cnn.com/2003/LAW/12/24/bush.clean.air.ap/index.html

http://www.cnn.com/

http://www.cnn.com/LAW/

Clean Air Act Clean Air Act http://www.epa.gov/air/oaq_caa.htmlhttp://www.epa.gov/air/oaq_caa.html

• Title I - Air Pollution Prevention and Control– Part A - Air Quality and Emission Limitations

– Part B - Ozone Protection (replaced by Title VI)

– Part C - Prevention of Significant Deterioration of Air Quality

– Part D - Plan Requirements for Nonattainment Areas

• Title II - Emission Standards for Moving Sources– Part A - Motor Vehicle Emission and Fuel Standards

– Part B - Aircraft Emission Standards

– Part C - Clean Fuel Vehicles

• Title III - General

• Title IV - Acid Deposition Control

• Title V - Permits

• Title VI - Stratospheric Ozone Protection

http://www.epa.gov/air/oaq_caa.html

Outdoor Air PollutionOutdoor Air Pollution

Primary PollutantsPrimary Pollutants

Secondary PollutantsSecondary Pollutants

SourcesSourcesNaturalNatural

StationaryStationary

COCO COCO22

SOSO22 NONO NONO22

Most hydrocarbonsMost hydrocarbons

Most suspendedMost suspendedparticlesparticles

SOSO33

HNOHNO33 HH22SOSO44

HH22OO22 OO33 PANsPANs

MostMost andand saltssaltsNONO33––

MobileMobile

SOSO4422 ––

Major Sources of Primary PollutantsMajor Sources of Primary Pollutants

Stationary Sources• Combustion of fuels for power and heat – Power Plants• Other burning such as Wood & crop burning or forest

fires• Industrial/ commercial processes• Solvents and aerosols

Mobile Sources• Highway: cars, trucks, buses and motorcycles• Off-highway: aircraft, boats, locomotives, farm

equipment, RVs, construction machinery, and lawn mowers

54 million metric tons from mobile sources in 1990

Human Impact on AtmosphereHuman Impact on Atmosphere• Burning Fossil Fuels

• Using Nitrogen fertilizers and burning fossil fuels

• Refining petroleum and burning fossil fuels

• Manufacturing

Adds CO2 and O3 to troposphere Global Warming Altering Climates Produces Acid Rain Releases NO, NO2, N2O, and NH3

into troposphere Produces acid rain Releases SO2 into troposphere

Releases toxic heavy metals (Pb, Cd, and As) into troposphere

www.dr4.cnrs.fr/gif-2000/ air/products.html

http://www.dr4.cnrs.fr/gif-2000/air/products.html

Criteria Air PollutantsCriteria Air PollutantsEPA uses six "criteria pollutants" as indicators of air quality

1. Nitrogen Dioxide: NO2

2. Ozone: ground level O3

3. Carbon monoxide: CO4. Lead: Pb5. Particulate Matter: PM10 (PM 2.5)

6. Sulfur Dioxide: SO2

• Volatile Organic Compounds: (VOCs)

EPA established for each concentrations above which adverse effects on health may occur

Nitrogen Dioxide (NONitrogen Dioxide (NO22))• Properties: reddish brown gas, formed as

fuel burnt in car, strong oxidizing agent, forms Nitric acid in air

• Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth

• Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil

• Class: Nitrogen oxides (NOx) • EPA Standard: 0.053 ppm

Mobile Source Emissions: Mobile Source Emissions: Nitrogen OxidesNitrogen Oxides

Ozone (OOzone (O33))• Properties: colorless, unpleasant odor,

major part of photochemical smog• Effects: lung irritant, damages plants,

rubber, fabric, eyes, • Sources: Created by sunlight acting on

NOx and VOC , photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products

• Class: photochemical oxidants

Ozone (OOzone (O33))• 10,000 to 15,000 people in US admitted to

hospitals each year due to ozone-related illness

• Children more susceptible– Airways narrower

– More time spent outdoors

Mobile Source Emissions: Mobile Source Emissions: Hydrocarbons – Hydrocarbons –

Precursors to OzonePrecursors to Ozone

Carbon Monoxide (CO)Carbon Monoxide (CO)• Properties: colorless, odorless, heavier than

air, 0.0036% of atmosphere

• Effects: binds tighter to Hb than O2, mental functions and visual acuity, even at low levels

• Sources: incomplete combustion of fossil fuels 60 - 95% from auto exhaust

• Class: carbon oxides (CO2, CO)

• EPA Standard: 9 ppm

• 5.5 billion tons enter atmosphere/year

Mobile Source Mobile Source Emissions - COEmissions - CO

Lead (Pb)Lead (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, batteries• Class: toxic or heavy metals• EPA Standard: 1.5 ug/m3

• 2 million tons enter atmosphere/year

Suspended Particulate Matter (PMSuspended Particulate Matter (PM1010)) •Properties: particles suspended in air (<10

um)

•Effects: lung damage, mutagenic, carcinogenic, teratogenic

•Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields

•Class: SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides

•EPA Standard: 50 ug/m3 (annual mean)

Mobile Source Emissions: Fine Mobile Source Emissions: Fine Particulate Matter (PMParticulate Matter (PM2.52.5))

Sulfur Dioxide (SOSulfur Dioxide (SO22)) • Properties: colorless gas with irritating odor• Effects: produces acid rain (H2SO4),

breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators

• Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture

• Class: sulfur oxides• EPA Standard: 0.3 ppm (annual mean)• Combines with water and NH4 to increase

soil fertility

VOCs (Volatile Organic Compounds)VOCs (Volatile Organic Compounds)• Properties: organic compounds (hydrocarbons) that

evaporate easily, usually aromatic • Effects: eye and respiratory irritants; carcinogenic; liver,

CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warming

• Sources: vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning

• Class: HAPs (Hazardous Air Pollutants) – Methane– Benzene– Chlorofluorocarbons (CFCs), etc.

• Concentrations indoors up to 1000x outdoors• 600 million tons of CFCs

Other Air PollutantsOther Air Pollutants• Carbon dioxideCarbon dioxide• CChlorohloroFFluoroluoroCCarbonsarbons• FormaldehydeFormaldehyde• BenzeneBenzene• AsbestosAsbestos• ManganeseManganese• DioxinsDioxins• CadmiumCadmium• Others not yet fully characterizedOthers not yet fully characterized

Formation & IntensityFormation & IntensityFactorsFactors• Local climate (inversions, air pressure, temperature, Local climate (inversions, air pressure, temperature,

humidity)humidity)• Topography (hills and mountains)Topography (hills and mountains)• Population densityPopulation density• Amount of industryAmount of industry• Fuels used by population and industry for heating, Fuels used by population and industry for heating,

manufacturing, transportation, powermanufacturing, transportation, power• Weather: rain, snow,windWeather: rain, snow,wind• Buildings (slow wind speed)Buildings (slow wind speed)• Mass transit usedMass transit used• Economics Economics

Pollutants

warmair

cool air

• surface heated by sun• warm air rises (incl. pollutants)• cools off, mixes with air of equal density & disperses

cool air

warm air (inversion layer)

• surface cools rapidly (night)• a layer of warm air overlays surface• polluted surface air rises but cannot disperse remains trapped

Thermal InversionThermal Inversion

...when polluted air is stagnant (weather conditions, geographic location)

Los Angeles, CA

Smog FormsSmog Forms

Primary PollutantsPrimary Pollutants

Secondary PollutantsSecondary Pollutants

SourcesSourcesNaturalNatural

StationaryStationary

COCO COCO22

SOSO22 NONO NONO22

Most hydrocarbonsMost hydrocarbons

Most suspendedMost suspendedparticlesparticles

SOSO33

HNOHNO33 HH22SOSO44

HH22OO22 OO33 PANsPANs

MostMost andand saltssaltsNONO33––

MobileMobile

SOSO4422 ––

Photochemical SmogPhotochemical Smog

Primary Pollutants

NO2 + Hydrocarbons

Auto Emissions

UV radiation

H2O + O2

Secondary Pollutants

HNO3 O3

nitric acid ozone

Photochemical Smog

Solarradiation

Ultraviolet radiation

NONitric oxide

P h o t o c h e m i c a l S m o g

H2OWater

NO2

Nitrogendioxide

Hydrocarbons

O2

Molecularoxygen

HNO3

Nitric acid

PANsPeroxyacyl

nitrates

Aldehydes(e.g., formaldehyde)

O3

Ozone

OAtomicoxygen

Photochemical Smog

Indoor Air PollutionIndoor Air Pollution

Why is indoor air quality Why is indoor air quality important?important?

• 70 to 90% of time spent indoors, mostly at home

• Many significant pollution sources in the home (e.g. gas cookers, paints and glues)

• Personal exposure to many common pollutants is driven by indoor exposure

• Especially important for susceptible groups – e.g. the sick, old and very young

ExposureExposure• Time spent in various environments in US

and less-developed countries

House of Commons Select Committee House of Commons Select Committee Enquiry on Indoor Air Pollution (1991)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…”

Sources of Indoor Air PollutantsSources of Indoor Air Pollutants• Building materials

• Furniture

• Furnishings and fabrics

• Glues

• Cleaning products

• Other consumer products

• Combustion appliances (cookers and heaters)

• Open fires

• Tobacco smoking

• Cooking

• House dust mites, bacteria and moulds

• Outdoor air

Important Indoor Air pollutantsImportant Indoor Air pollutants• Nitrogen dioxide

• Carbon monoxide

• Formaldehyde

• Volatile Organic Compounds (VOCs)

• House dust mites (and other allergens, e.g. from pets)

• Environmental tobacco smoke

• Fine particles

• Chlorinated organic compounds (e.g. pesticides)

• Asbestos and man-made mineral fibres

• Radon

Health EffectsHealth EffectsNitrogen dioxide• Respiratory irritant• Elevated risk of respiratory illness in children,

perhaps resulting from increased susceptibility to respiratory infection; inconsistent evidence for effects in adults

• Concentrations in kitchens can readily exceed WHO and EPA standards

Health EffectsHealth Effects

Carbon monoxide• An asphyxiant and toxicant

• Hazard of acute intoxication, mostly from malfunctioning fuel-burning appliances and inadequate or blocked fumes

• Possibility of chronic effects of long-term exposure to non- lethal concentrations, particularly amongst susceptible groups


Formaldehyde• Sensory and respiratory irritant and sensitizer

• Possible increased risk of asthma and chronic bronchitis in children at higher exposure levels

• Individual differences in sensory and other transient responses

• Caution over rising indoor concentrations


Volatile Organic Compounds (VOCs)• Occur in complex and variable mixtures

• Main health effects relate to comfort and well-being, but benzene (and other VOCs) are carcinogenic

• Concern about possible role of VOCs in the aetiology of multiple chemical sensitivity; also implicated in sick building syndrome


House dust mites• House dust mites produce Der p1 allergen, a potent

sensitizer• Good evidence of increased risk of sensitization with

increasing allergen exposure, but this does not necessarily lead to asthma

• Small reductions in exposure will not necessarily lead to reduced incidence and/or symptoms

• Indoor humidity is important


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 disease

• Insufficient data to relate exposure to (non-pathogenic) bacteria to health effects in the indoor environment


Environmental tobacco smoke (ETS)• Sudden infant death syndrome • Lower respiratory tract illness • Middle ear disease • Asthma

12 million children exposed to secondhand 12 million children exposed to secondhand smoke in homessmoke in homes

Health EffectsHealth EffectsFine particles• Consistent evidence that exposure to small

airborne particles (e.g. PM10) in ambient air can impact on human health; mechanisms uncertain

• Chronic Obstructive Pulmonary Disease and Cardiovascular Disease patients and asthmatics probably at extra risk

• Relative importance of indoor sources is unknown


Radon• Can cause lung cancer

• Estimated that 7,000 to 30,000 Americans die each year from radon-induced lung cancer

• Only smoking causes more lung cancer deaths

• Smokers more at risk than non-smokers

Radon Risk: Non-SmokerRadon Risk: Non-SmokerRadon Level

(pCI/L)

If 1000 people who did not smoke were exposed to this level over a lifetime..

About X would get lung cancer

This risk of cancer from radon exposure compares

to …What to do:

20 8 Being killed in a violent crime

Fix your home

10 4 Fix your home

8 3 10x risk of dying in a plane crash

Fix your home

4 2 Risk of drowning Fix your home

2 <1 Risk of dying in a home fire

Fix your home

1.3 <1 Average indoor radon level

Fix your home

.4 <1 Average indoor radon level

Fix your home

If you are a former smoker, your risk may be higherIf you are a former smoker, your risk may be higher

Radon Risk: SmokerRadon Risk: SmokerRadon Level

(pCI/L)

If 1000 people who smoke were exposed to this level over a lifetime..

About X would get lung cancer

This risk of cancer from radon exposure compares

to …

What to do:

Stop smoking and …

20 135 100x risk of drowning Fix your home

10 71 100x risk of dying in a home fire

Fix your home

8 57 Fix your home

4 29 100x risk of dying in a plane crash

Fix your home

2 15 2x the risk of dying in a car crash

Fix your home

1.3 9 Average indoor radon level

Fix your home

.4 3 Average indoor radon level

Fix your home

If you are a former smoker, your risk may be lowerIf you are a former smoker, your risk may be lower

RadonRadon

• 55% of our exposure to radiation comes from radon

• colorless, tasteless, odorless gas

• formed from the decay of uranium

• found in nearly all soils

• levels vary

(From: http://www.epa.gov/iaq/radon/zonemap.html)

Zone pCi/L 1 >4 2 2 - 4 3 <2

Radon: How it Enters BuildingsRadon: How it Enters Buildings

• Cracks in solid floors• Construction joints• Cracks in walls• Gaps in suspended floors• Gaps around service pipes• Cavities inside walls• The water supply

http://www.epa.gov/iaq/radon/pubs/citguide.html#howdoes

Radon: Reducing the RisksRadon: Reducing the Risks• Sealing cracks in floors and walls • Simple systems using pipes and fans

• More information:

http://www.epa.gov/iaq/radon/pubs/consguid.html#reductiontech

Sick Building Syndrome (SBS)Sick Building Syndrome (SBS)

vsvs

Building Related Illness (BRI)Building Related Illness (BRI)

Sick Building SyndromeSick Building Syndrome

• A persistent set of symptoms in > 20% population

• Causes(s) not known or recognizable• Complaints/Symptoms relieved after exiting

building

Complaints/SymptomsComplaints/Symptoms

• Headaches

• Fatigue

• Reduced Mentation

• Irritability

• Eye, nose or throat irritation

• Dry Skin

• Nasal Congestion

• Difficulty Breathing

• Nose Bleeds

• Nausea

Building Related IllnessBuilding Related Illness• Clinically Recognized Disease

• Exposure to indoor air pollutants

• Recognizable Causes

Clinically Recognized DiseasesClinically Recognized Diseases

–Pontiac Fever – Legionella spp.

–Legionnaire's Disease

–Hypersensitivity Pneumonitis

–Humidifier Fever

–Asthma

–Allergy

–Respiratory Disease• Chronic Obstructive Pulmonary Disease

VentilationVentilation

Movement of Air Into / Out of HomesMovement of Air Into / Out of Homes• Amount of air available to dilute pollutants

– important indicator of the likely contaminant concentration

• Indoor air can mix with outside air by three mechanisms– infiltration

– natural ventilation

– forced ventilation

Movement of Air Into / Out of HomesMovement of Air Into / Out of Homes• Infiltration

– natural air exchange that occurs between a building and its environment when the doors and windows are closed

– leakage through holes or openings in the building envelope

– pressure induced• due to pressure differentials inside and outside of the

building

• especially important with cracks and other openings in wall

Movement of Air Into / Out of HomesMovement of Air Into / Out of Homes

• Infiltration– Temperature induced (stack effect)

• driven by air movement through holes in floors, ceilings

• in winter, warm air in a building wants to rise, exits through cracks in ceiling and draws in

Movement of Air Into / Out of HomesMovement of Air Into / Out of Homes• Natural ventilation

– air exchange that occurs when windows or doors are opened to increase air circulation

• Forced ventilation– mechanical air handling systems used to induce air

exchange using fans and blowers

• Trade-offs– cut infiltration to decrease heating and cooling costs vs.

indoor air quality problems

Movement of Air Into / Out of HomesMovement of Air Into / Out of Homes• Infiltration rates

– Influenced by• how fast wind is blowing, pressure differentials• temperature differential between inside and

outside of house• location of leaks in building envelope

Greenhouse EffectGreenhouse Effect

http://royal.okanagan.bc.ca/mpidwirn/atmosphereandclimate/cascade.html

http://royal.okanagan.bc.ca/mpidwirn/atmosphereandclimate/cascade.html

Natural Greenhouse EffectNatural Greenhouse Effect

• With Greenhouse Effect average global temperature 60 degrees

• Without it, Earth would be a frigid planet, with average temperature around zero degrees Fahrenheit

Global WarmingGlobal Warming

CO2 CFCs CH4

Increased Greenhouse Gases in the Troposphere

Excess heat

Greenhouse GasesGreenhouse GasesCarbon dioxide

Methane

Nitrous oxide

Ozone

CFC’s

Hydrofluorocarbons

Perfluorinated carbons

Water vapour

Average Temperature Over Past 900,000 YearsAverage Temperature Over Past 900,000 Years

Thousands of Years Ago

Ave

rag

e S

urf

ace

Tem

per

atu

re (

°C)

900 800 700 600 500 400 300 200 100 Present9

10

11

12

13

14

15

16

17

Temperature Change Over Past 22,000 YearsTemperature Change Over Past 22,000 Years

Years Ago

Tem

per

atu

re C

han

ge

(°C

)

20,000 10,000 2,000 1,000 200 100 Now

-5

-4

-3

-2

-1

0

1

2

End oflast ice

age

Agriculture established

Average temperature over past10,000 years = 15°C (59°F)

Average Temperature Over Past 130 YearsAverage Temperature Over Past 130 Years

Year

Ave

rag

e S

urf

ace

Tem

per

atu

re (

°C)

1860 1880 1900 1920 1940 1960 1980 2000 2020

13.6

13.8

14.0

14.2

14.4

14.6

14.8

15.0

Is this increase in Is this increase in temperature natural temperature natural

or ?or ?

Carbon dioxide

Temperaturechange End of

last ice age

160 120 80 40 0

Thousands of Years Before Present

Co

nce

ntr

atio

n o

f C

O2

in t

he

Atm

osp

her

e (p

pm

)

180

200

220

240

260

280

300

320

340

360

380

–10.0

–7.5

–5.0

–2.5

0

+2.5

Var

iati

on

of

tem

per

atu

re (

˚C)

fro

m c

urr

ent

leve

l

Year1990 2000 2025 2050 2075 2100

100

150

200

250

Ind

ex (

1900

= 1

00)

Carbon dioxide

MethaneNitrous oxide

Measurements made at Mauna Loa, Hawaii; elevation = 12,000 feet

Contribution to Contribution to Greenhouse Greenhouse

EffectEffect

MethaneMethane• Core 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 years

• short 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.

MethaneMethane• Temperatures 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 gas

• Methane was released due to breakdown of material associated with permafrost

Year1850 1875 1900 1925 1950 1975 2000 2025 2050 2075 21000

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Ch

ang

e in

Tem

per

atu

re (

ºC)

Predictions of Future Warming?Predictions of Future Warming?

Top Greenhouse Gas Top Greenhouse Gas EmittersEmitters

• 19.1 % - United States• 9.9% - China• 5.1% - Japan• 4.3% - Brazil• 3.8 % - Germany• 3.7% - Japan• 2.4% - United Kingdom• 1.9% - Indonesia• 1.7% - Italy

What impacts have What impacts have occurred and are occurred and are

predicted to occur predicted to occur from global warming?from global warming?

?

Atmosphere Impacts from Global Warming?Atmosphere Impacts from Global Warming?

WeatherOcean currents

Sea levelWater resources

BiodiversityForests

Human healthAgriculture

Human demographics

• Increased deaths from heat and disease

• Disruption of food and water supplies

• Spread of tropical diseases to temperate areas

• Increased respiratory disease

• Increased water pollution from coastal flooding

Human Health

• Rising sea levels• Flooding of low-lying islands and

coastal cities• Flooding of coastal estuaries,

wetlands, and coral reefs• Beach erosion• Disruption of coastal fisheries• Contamination of coastal aquifiers

with salt water

Sea Level and Coastal Areas

• Changes in forest composition and locations

• Disappearance of some forests

• Increased fires from drying

• Loss of wildlife habitat and species

Forests

• Changes in water supply

• Decreased water quality

• Increased drought

• Increased flooding

Water Resources

• Shifts in food-growing areas

• Changes in crop yields

• Increased irrigation demands

• Increased pests, crop diseases, and weeds in warmer areas

Agriculture

• Extinction of some plant and animal species

• Loss of habitats

• Disruption of aquatic life

Biodiversity

• Prolonged heat waves and droughts

• Increased flooding

• More intense hurricanes, typhoons, tornadoes, and violent storms

Weather Extremes

• Increased deaths

• More environmental refugees

• Increased migration

Human Population

Direct manifestationsDirect manifestations

• Heat waves and periods of unusually warm weather

• Sea level rise and coastal flooding

• Glaciers melting

• Arctic and Antarctic warming with ice shelves breaking up

• Increase severity of weather

• Zooplankton are dying in the Pacific Ocean

Heat wave kills 30, no relief in sight July 27, 1999

http://www.cnn.com/WEATHER/9907/27/heat.wave.02/index.html

Monster iceberg breaks off Antarctic ice shelf May 10, 2002

http://www.cnn.com/2002/TECH/space/05/09/iceberg.satellite/index.html

Antarctica

Cold water melting fromAntarctica's ice cap and

icebergs falls to the ocean floor and surges northward, affecting

worldwide circulation.

Cold water melting fromAntarctica's ice cap and

icebergs falls to the ocean floor and surges northward, affecting

worldwide circulation.

GreenlandGreenland

Today’s sea level

Years before present Present

250,000 200,000 150,000 100,000 50,000 0

–130

0

–426

0

Hei

gh

t ab

ove

or

bel

ow

pre

sen

t se

a le

vel

(met

ers)

Hei

gh

t b

elo

w p

rese

nt

sea

leve

l (f

eet)

If all the ice on Greenland melted, If all the ice on Greenland melted, world sea levels would rise about six world sea levels would rise about six

metres (20 feet)metres (20 feet)

If all the ice on the Antarctic continent If all the ice on the Antarctic continent melted, sea levels would rise over 70 melted, sea levels would rise over 70

metres (230 feet)metres (230 feet)

This is unlikely to happen, but small This is unlikely to happen, but small increases will continue.increases will continue.

Possible ConsequencesPossible Consequences

• Spreading disease

• Earlier spring arrival

• Plant and animal range shifts and population declines

• Coral reef bleaching

• Downpours, heavy snowfalls, and flooding

• Droughts and fires

Global warming may harm human health November 16, 1998Climatic changes related to global warming could foster dangerous outbreaks of cholera, dengue fever and malaria, …

http://www.cnn.com/TECH/science/9811/16/climate.health.enn/index.html

Study: Global warming spurs migrations Thursday, January 2, 2003

Rising 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. http://www.cnn.com/2003/TECH/science/01/02/climate.migrations.ap/index.html

http://www.cnn.com/2003/TECH/science/01/02/climate.migrations.ap/index.html

Report: Coral bleaching hits record level May 19, 1999 Global warming has been linked to an unprecedented episode of coral bleaching in 1998, …

http://www.cnn.com/NATURE/9905/19/coral.bleaching.enn/index.html

http://www.cnn.com/NATURE/9905/19/coral.bleaching.enn/index.html

Vicious cycle: Global warming feeds fire potentialNovember 2, 2000 Global warming may greatly accelerate the fire cycle in the desert ecosystem of North America, according to a study published today in the journal Nature. Elevated carbon dioxide levels, the result of increased fossil fuel burning, can alter the delicate balance of grasses in desert areas, the report notes. This finding may have major implications for the biodiversity and health of desert ecosystems in the western United States. "This could be a real problem for land managers," said Stan Smith, a professor of biology at the University of Nevada in Las Vegas and lead author of the study. http://www.cnn.com/2000/NATURE/11/02/global.warming.enn/index.html

http://www.cnn.com/2000/NATURE/11/02/global.warming.enn/index.html

http://www.soton.ac.uk/~engenvir/environment/air/greenhouse.problems.html

http://www.soton.ac.uk/~engenvir/environment/air/greenhouse.problems.html

Anomaly = difference between actual value and some mean value; in this case the mean is a 30 year average

Warmest Years on RecordWarmest Years on Record

• 1981

• 1983

• 1987

• 1988

• 1989

• 1990

• 1991

• 1994• 1995• 1996• 1997• 1998• 1999• 2000• 2001

Ozone HoleOzone Hole

Understanding Ozone Understanding Ozone http://royal.okanagan.bc.ca/mpidwirn/atmosphereandclimate/ozonehole.htmlhttp://royal.okanagan.bc.ca/mpidwirn/atmosphereandclimate/ozonehole.html

• Discovered in 1839 by German scientist Christian Friedrich Schonbein

• Pale blue, unstable molecule made of three oxygen atoms• Vital to life in the stratosphere • Harmful to plants and humans in the troposphere• Concentration: stratosphere up to 15 ppm at about 25 km• Formed when atomic oxygen (O) from higher parts of the

atmosphere collides with molecular oxygen (O2) in the stratosphere

• UV radiation splits the ozone back to O and O2 and it can form another ozone molecule

http://royal.okanagan.bc.ca/mpidwirn/atmosphereandclimate/ozonehole.html

http://www-imk.fzk.de/topoz-iii/ataglanz/ozonbild.html

http://www-imk.fzk.de/topoz-iii/ataglanz/ozonbild.html

http://www-imk.fzk.de/topoz-iii/ataglanz/ozonzerst.html

http://www-imk.fzk.de/topoz-iii/ataglanz/ozonzerst.html

The Ozone HoleThe Ozone Hole• First 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 December

• Ozone hole caused by human chemicals (CFC’s)• Ozone hole not present in early 1970’s

science.widener.edu/svb/ atmo_chem/oct15.html

http://science.widener.edu/svb/atmo_chem/oct15.html

Ozone hole stabilizesOctober 17, 2001WASHINGTON (CNN) -- A hole in the Earth's protective ozone layer is about the same size as in the past three years, according to scientists at the National Oceanic and Atmospheric Administration,

who predict it will hold steady in the near future.

Satellite data show the hole over Antarctica, which allows more harmful solar radiation to

reach the Earth, peaked this year at about 10 million square miles (26 million square km), roughly the size of North America.

http://www.cnn.com/2001/TECH/space/10/17/ozone.hole.size/index.html




History of Ozone DepletionHistory of Ozone Depletion• CFCs developed in 40’s and 50’sCFCs developed in 40’s and 50’s

– Refrigerants, propellants, fire retardantsRefrigerants, propellants, fire retardants

• 1970’s CFCs detected in atmosphere.1970’s CFCs detected in atmosphere.– Many of these have long atmospheric lifetimes (10’s to 100’s of years)Many of these have long atmospheric lifetimes (10’s to 100’s of years)

• 1974 Rowland and Molina propose that CFC’s can destroy 1974 Rowland and Molina propose that CFC’s can destroy ozone in the stratosphere.ozone in the stratosphere.– CFCs broken apart by UV radiation forming chlorine which can CFCs broken apart by UV radiation forming chlorine which can

destroy ozone quickly:destroy ozone quickly:• O3 +Cl ClO+ O2 (Catalytic Reaction)

• ClO+O Cl+O2

Chlorofluorocarbons or CFCsChlorofluorocarbons or CFCs

• First produced by General Motors First produced by General Motors Corporation in 1928, CFCs were created as a Corporation in 1928, CFCs were created as a replacement to the toxic refrigerant replacement to the toxic refrigerant ammoniaammonia

• CFCs have also been used as a propellant in CFCs have also been used as a propellant in spray cans, cleaner for electronics, sterilant spray cans, cleaner for electronics, sterilant for hospital equipment, and to produce the for hospital equipment, and to produce the bubbles in Styrofoambubbles in Styrofoam

• CFCs 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.

Action of CFCsAction of CFCs

• CFCs created at the Earth's surface drift slowly CFCs created at the Earth's surface drift slowly upward to the stratosphere where UV radiation upward to the stratosphere where UV radiation from the sun causes their decomposition and the from the sun causes their decomposition and the release of chlorinerelease of chlorine

• Chlorine in turn attacks the molecules of ozone Chlorine in turn attacks the molecules of ozone converting them into oxygen moleculesconverting them into oxygen molecules

Cl + OCl + O33 »»» ClO + O »»» ClO + O22

ClO + O »»» Cl + OClO + O »»» Cl + O22

Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breakingoff a chlorine atom and leaving CFCl2.

UV radiation

Sun

Once free, the chlorine atom is off to attack another ozone moleculeand begin the cycle again.

A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O2.

The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO)

The chlorine atom attacksan ozone (O3) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O2).

Cl

Cl

ClC

F

Cl

Cl

OO

Cl

OO

O

ClO

OO

ClO

O

http://www.clas.ufl.edu/users/dlsmith/Lecture_11.html

http://www.clas.ufl.edu/users/dlsmith/Lecture_11.html

A single chlorine atom A single chlorine atom removes about 100,000 removes about 100,000

ozone molecules before it ozone molecules before it is taken out of operation is taken out of operation

by other substancesby other substances

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

Low and Middle LatitudesLow and Middle Latitudes

Harmful effects of UV Harmful effects of UV radiation.radiation.

• Skin cancer (ultraviolet radiation can destroy acids in DNA)

• Cataracts and sun burning• Suppression of immune systems• Adverse impact on crops and animals• Reduction in the growth of ocean

phytoplankton • Cooling of the Earth's stratosphere and

possibly some surface climatic effect• Degradation of paints and plastic material

matrix.ucdavis.edu/tumors/tradition/ gallery-ssmm.html

http://matrix.ucdavis.edu/tumors/tradition/gallery-ssmm.html

www.snec.com.sg/clinical_services/ cataract.asp

http://www.snec.com.sg/clinical_services/cataract.asp

ConclusionConclusion• Ozone Depletion Exists and effects certain

areas of the Earth more than others• Currently, one in five North Americans and

one in two Australians will develop some form of skin cancer in their lifetime

• With 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.

Acid DepositionAcid Deposition

Measuring Acid Measuring Acid RainRain• 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 5.6

• Any rainfall has a pH value less than 5.6 is defined as acid rain

• As of the year 2000, the most acidic rain falling in the US has a pH of about 4.3.

Two Forms…Two Forms…• Wet

Refers to acid rain, fog, sleet, cloud vapor and snow.

• Dry

Refers to acidic gases and particles.

CompoundsCompounds

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.

When 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)

Causes of Causes of Acid RainAcid Rain

• Sulfur 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.

Acidic PrecipitationAcidic Precipitation

Fossil fuelsPower plants

Industrial emissionsAuto emissions

Primary PollutantsSO2

NO2

Secondary Pollutants

H2SO4 HNO2

sulfuric acid nitric acid

soilsleaching of minerals

vegetationdirect toxicity

indirect health effects

water

sedimentsleaching aluminum

acidic precipitation

Wind

Transformation tosulfuric acid (H2SO4)and nitric acid (HNO3)

Nitric oxide (NO)

Acid fog

Ocean

Sulfur dioxide (SO2)and NO

Windborne ammonia gasand particles of cultivated soilpartially neutralize acids and

form dry sulfate and nitrate salts

Dry aciddeposition

(sulfur dioxidegas and particles

of sulfate andnitrate salts)

Farm

Lakes indeep soil

high in limestoneare buffered

Lakes in shallowsoil low inlimestonebecomeacidic

Wet acid deposition(droplets of H2SO4 andHNO3 dissolved in rain

and snow)

AcidicAcidicPrecipitationPrecipitation

Fig. 17.10, p. 428BIOL 349

Atmosphere

Sulphur dioxide emission (1997)

““Wet” Acid Wet” Acid RainRain

• Acidic water flows over and through the ground, it affects a variety of plants and animals.

““Dry” Acid RainDry” Acid Rain• Dry deposition refers to acidic

gases and particles.

• About half of the acidity in theatmosphere falls back to earth through dry deposition.

• The wind blows these acidic particles and gases onto buildings, cars, homes, and trees.

http://svr1-pek.unep.net/soechina/images/acid.jpg

http://svr1-pek.unep.net/soechina/images/acid.jpg

Increased Increased AcidityAcidity

• Dry 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.

Effects of Acid Effects of Acid RainRain

• The strength of the effects depend on many factors– How acidic the water is

– The chemistry and buffering capacity of the soils involved

– The types of fish, trees, and other living things that rely on the water

Effects of Acid Effects of Acid RainRain

• Has 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 environments

• Most lakes and streams have a pH between 6 and 8

http://cica.indiana.edu/projects/Biology/movies.html

http://cica.indiana.edu/projects/Biology/movies.html

Buffering CapacityBuffering Capacity• Acid 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.

• In 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.

http://home.earthlink.net/~photofish/fish_photos/sw10_thumb.jpg

http://home.earthlink.net/~photofish/fish_photos/sw10_thumb.jpg

Effects on WildlifeEffects on Wildlife• Generally, 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.

Effects on WildlifeEffects on Wildlife• Both 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.

Acid Rain and ForestsAcid 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.

GermanyGermanyMongoliaMongolia

Effects Effects of Acid of Acid

RainRain

Great Smoky Mountains, NC

NutrientsNutrients• Acidic 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.

Air Pollution PreventionAir Pollution Prevention

Specific Air Pollution Treatment Specific Air Pollution Treatment TechnologyTechnology

• Traditional– Move factory to remote location– Build taller smokestack so wind blows pollution

elsewhere

• New– Biofiltration : vapors pumped through soil where

microbes degrade– High-energy destruction: high-voltage electricity – Membrane separation: diffusion of organic

vapors through membrane– Oxidation: High temperature combustor

AbsorptionAbsorption

AdsorptionAdsorption

CombustionCombustion

CycloneCyclone

FiltrationFiltration

Electrostatic PrecipitatorElectrostatic Precipitator

Liquid ScrubberLiquid Scrubber

Sulfur Dioxide Sulfur Dioxide ControlControl

http://www.apt.lanl.gov/projects/cctc/factsheets/puair/adflugasdemo.html

Air Pollution ResultsAir Pollution Results

Comparison of 1970 and 1999 EmissionsComparison of 1970 and 1999 Emissions

Number of People Living in Counties with Air Quality Number of People Living in Counties with Air Quality Concentrations Above the Level of the Concentrations Above the Level of the National Ambient National Ambient

Air Quality Standards (Air Quality Standards (NAAQS) in 1999NAAQS) in 1999

Trends in Sulfur Dioxide Emissions Following Trends in Sulfur Dioxide Emissions Following Implementation of Phase I of the Acid Rain Implementation of Phase I of the Acid Rain

Program: Total State-level Utility SO2 (1980, 1990, Program: Total State-level Utility SO2 (1980, 1990, 1999)1999)

FiftyFiftyYearsYears

ofofAirAir

PollutioPollutionn

30

20

10

00

VOC Stationary

Mobile

755025

0

CO

100

Mobile

Stationary

1940 1950 1960 1970 1980 1990

1510

5

0

NOx

20

Mobile

Stationary

Figures are in millions of metric tons per year

MobileMobileSources:Sources:The LastThe Last

Ten Ten YearsYears

-10%

-29%

-8%

-85%

-3%

-24%

VOCs CO NOx PM10 SOx Lead

Percent reductions shown are based on estimates of tons/year from mobile sources over the 1981 - 1990 time period

Who isWho isAffected Affected

bybyAir Air

Pollution?Pollution?

63

22

9

19

15

Ozone CO NO2 PM10 SO2 Lead

Millions of people living in counties with air quality that exceeds each NAAQS (1990 data)

Over 74 million people are subjected to high levels of at least one of these pollutants

MilestonesMilestonesin thein the

ControlControlofof

AutomotiveAutomotiveEmissionsEmissions

1952 - Autos linked to air pollution

1963 - Original CAA, PCV valves

1968 - HC & CO exhaust controls

1970 - CAA amendments, EPA formed

1971 - Evaporative controls

1972 - First I/M Program

1973 - NOx exhaust controls

1975 - First catalytic converters

1981 - New cars meet statutory limits

1989 - Volatility limits on gasoline

1990 - New CAA Amendments

•1987 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.

What is the Kyoto Protocol?What is the Kyoto Protocol?

How did we get to Kyoto?

What are the goals of Kyoto?

Is Kyoto enough?

Steps to KyotoSteps to Kyoto

1985 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”

Steps to KyotoSteps to Kyoto

1988 - Toronto - creation of IPCCwarmest summer to date, international meeting in

Toronto

Intergovernmental Panel on Climate Change formed

1990 - First report (FAR)overview of the current science of climate change

IPCCIPCC

IPCC headed by Prof. Bert Bolin3 working groups

Climate Science

Climate Impacts

Response Strategies

1992 - FAR used in Earth Summit meeting in Rio - United Nations Framework Convention on Climate Change

IPCCIPCC

1995 IPCC Second Assessment Report (SAR) completed, published in 1996

WG I Climate Science

WG II Impact, Adaptation and Mitigation

WG III Economic and Social Dimensions

“The balance of evidence suggests a discernible human influence on global climate”

IPCCIPCC

1997 Kyoto meeting - binding targets setculmination of a series of meetings since Rio

(1992)

2001 Bonn - rescuing Kyoto

2001 IPCC Third Assessment Report (TAR)

WG I Climate Science

WG II Vulnerabilities, Impacts and Adaptation

WG III Mitigation

IPCCIPCC

TAR (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)

Goals of Kyoto ProtocolGoals of Kyoto Protocol

Reduction of greenhouse gases to below 1990 levels:

5.2% world wide reduction on average by 2008-2012

6% for Canada by 2008-2012

When sufficient countries ratify the Protocol (at least 55 countries comprising at least

55% of emissions), Protocol comes into effectUSA - 25% of emissions

Kyoto Emissions Agreement

Annex B Countries Non Annex B Countries

Fossil-Fuel CO

2 Emissions

(million metric

tonnes C)

Bunkers (million metric

tonnes C)

Fossil-Fuel CO2

Emissions (million metric

tonnes C)

Bunkers (million metric

tonnes C)

1990 3851 78 2126 41

1991 3751 88 2306 41

1992 3663 92 2291 43

1993 3610 92 2341 48

1994 3607 92 2487 50

1995 3624 95 2607 52

1996 3674 95 2704 58

1997 3696 97 2775 61

1998 3690 100 2756 62

Source: Gregg Marland and Tom Boden (CDIAC, Oak Ridge National Laboratory).

http://cdiac.esd.ornl.gov/trends/emis/annexb_countries.htm

http://cdiac.esd.ornl.gov/trends/emis/nonannexb_countries.htm

http://cdiac.esd.ornl.gov/trends/emis/annex_text.htm





http://cdiac.esd.ornl.gov/

Greenhouse Effect - Conclusion Greenhouse Effect - Conclusion

• Since 1700, humans have directly or Since 1700, humans have directly or indirectly caused the concentration indirectly caused the concentration of the major greenhouse gases to of the major greenhouse gases to increaseincrease

• Scientists predict that this increase Scientists predict that this increase may enhance the greenhouse effect may enhance the greenhouse effect making the planet warmer by 0.3 to making the planet warmer by 0.3 to 0.6 degrees Celsius0.6 degrees Celsius

Cost of Regular GasolineCost 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

History of Global WarmingHistory of Global Warming

1904: Swedish scientist Svante 1904: Swedish scientist Svante Arrhenius was, according to NASA, Arrhenius was, according to NASA, "the first person to investigate the "the first person to investigate the effect that doubling atmospheric effect that doubling atmospheric carbon dioxide would have on carbon dioxide would have on global climate." global climate."


Arrhenius began studying rapid Arrhenius began studying rapid increases in anthropogenic – carbon increases in anthropogenic – carbon emissions, determining that "the emissions, determining that "the slight percentage of carbonic acid in slight percentage of carbonic acid in the atmosphere may, by the advances the atmosphere may, by the advances of industry, be changed to a of industry, be changed to a noticeable degree in the course of a noticeable degree in the course of a few centuries." few centuries."


The unique research of Arrhenius The unique research of Arrhenius suggested that this increase could be suggested that this increase could be beneficial, making Earth's climates beneficial, making Earth's climates "more equable" and stimulating plant "more equable" and stimulating plant growth and food production. Until growth and food production. Until about 1960, most scientists thought it about 1960, most scientists thought it implausible that humans could actually implausible that humans could actually affect average global temperatures. affect average global temperatures.


1950s: Geophysicist Roger 1950s: Geophysicist Roger Revelle, with the help of Hans Revelle, with the help of Hans Suess, demonstrated that carbon Suess, demonstrated that carbon dioxide levels in the air had dioxide levels in the air had increased as a result of the use of increased as a result of the use of fossil fuels. fossil fuels.


1965: Serving on the President's Science 1965: Serving on the President's Science Advisory Committee Panel on Advisory Committee Panel on Environmental Pollution in 1965, Roger Environmental Pollution in 1965, Roger Revelle helped publish the first high-level Revelle helped publish the first high-level government mention of global warming. government mention of global warming. The book-length report identified many of The book-length report identified many of the environmental troubles the nation the environmental troubles the nation faced, and mentioned in a "subpanel faced, and mentioned in a "subpanel report" the potential for global warming by report" the potential for global warming by carbon dioxide. carbon dioxide.


1977: "In 1977 the nonpartisan 1977: "In 1977 the nonpartisan National Academy of Sciences issued a National Academy of Sciences issued a study called Energy and Climate, study called Energy and Climate, which carefully suggested that the which carefully suggested that the possibility of global warming 'should possibility of global warming 'should lead neither to panic nor to lead neither to panic nor to complacency.'complacency.'


Rather, the study continued, it Rather, the study continued, it should 'engender a lively sense of should 'engender a lively sense of urgency in getting on with the work urgency in getting on with the work of illuminating the issues that have of illuminating the issues that have been identified and resolving the been identified and resolving the scientific uncertainties that scientific uncertainties that remain.'remain.'


As is typical with National Academy As is typical with National Academy studies, the primary recommendation studies, the primary recommendation was for more research." — From was for more research." — From "Breaking the Global-Warming "Breaking the Global-Warming Gridlock" by Daniel Sarewitz and Gridlock" by Daniel Sarewitz and Roger Pielke Jr., THE ATLANTIC, Roger Pielke Jr., THE ATLANTIC, July 2000 July 2000


Roger Revelle chaired the National Roger Revelle chaired the National Academy Panel, which found that about Academy Panel, which found that about forty percent of the anthropogenic carbon forty percent of the anthropogenic carbon dioxide has remained in the atmosphere, dioxide has remained in the atmosphere, two-thirds from fossil fuel and one-third two-thirds from fossil fuel and one-third from the clearing of forests. It is now from the clearing of forests. It is now known that carbon dioxide is one of the known that carbon dioxide is one of the primary greenhouse gases that contributes primary greenhouse gases that contributes to global warming and remains in the to global warming and remains in the atmosphere for a century. atmosphere for a century.


1980s: Representative Al Gore (D-1980s: Representative Al Gore (D-TN), who had been a student of TN), who had been a student of Revelle's, co-sponsored the first Revelle's, co-sponsored the first Congressional hearings to study the Congressional hearings to study the implications of global warming and implications of global warming and to encourage the development of to encourage the development of environmental technologies to environmental technologies to combat global warming. combat global warming.


1982: Roger Revelle published a 1982: Roger Revelle published a widely-read article in SCIENTIFIC widely-read article in SCIENTIFIC AMERICAN addressing the rise in AMERICAN addressing the rise in global sea level and the "relative global sea level and the "relative role played by the melting of glaciers role played by the melting of glaciers and ice sheets versus the thermal and ice sheets versus the thermal expansion of the warming surface expansion of the warming surface waters." waters."


1983: The Environmental 1983: The Environmental Protection Agency released a Protection Agency released a report detailing some of the report detailing some of the possible threats of the possible threats of the anthropogenic emission of anthropogenic emission of carbon dioxide. carbon dioxide.


1988: NASA climate scientist James Hansen 1988: NASA climate scientist James Hansen and his team reported to Congress on global and his team reported to Congress on global warming, explaining, "the greenhouse warming, explaining, "the greenhouse warming should be clearly identifiable in the warming should be clearly identifiable in the 1990s" and that "the temperature changes are 1990s" and that "the temperature changes are sufficiently large to have major impacts on sufficiently large to have major impacts on people and other parts of the biosphere, as people and other parts of the biosphere, as shown by computed changes in the frequency shown by computed changes in the frequency of extreme events and comparison with of extreme events and comparison with previous climate trends." previous climate trends."


With the increased awareness of global With the increased awareness of global warming issues, the Intergovernmental Panel warming issues, the Intergovernmental Panel on Climate Change (IPCC) was established by on Climate Change (IPCC) was established by the World Meteorological Organization and the the World Meteorological Organization and the United Nations Environment Programme to United Nations Environment Programme to assess scientific, technical and socio-economic assess scientific, technical and socio-economic information relevant for the understanding of information relevant for the understanding of climate change, its potential impacts and climate change, its potential impacts and options for adaptation and mitigation. The options for adaptation and mitigation. The IPCC was the first international effort of this IPCC was the first international effort of this scale to address environmental issues. scale to address environmental issues.

History of Global WarmingHistory of Global Warming1990: Congress passed and President George 1990: Congress passed and President George Bush signed Public Law 101-606 "The Global Bush signed Public Law 101-606 "The Global Change Research Act of 1990. The purpose of the Change Research Act of 1990. The purpose of the legislation was "…to require the establishment of legislation was "…to require the establishment of a United States Global Change Research a United States Global Change Research Program aimed at understanding and responding Program aimed at understanding and responding to global change, including the cumulative effects to global change, including the cumulative effects of human activities and natural processes on the of human activities and natural processes on the environment, to promote discussions towards environment, to promote discussions towards international protocols in global change research, international protocols in global change research, and for other purposes." and for other purposes."

History of Global WarmingHistory of Global Warming•As part of the Act, the Global Change As part of the Act, the Global Change Research Information Office (GCRIO) was Research Information Office (GCRIO) was established "to disseminate to foreign established "to disseminate to foreign governments, businesses, and institutions, governments, businesses, and institutions, as well as citizens of foreign countries, as well as citizens of foreign countries, scientific research information available in scientific research information available in the United States which would be useful in the United States which would be useful in preventing, mitigating, or adapting to the preventing, mitigating, or adapting to the effects of global change. The office began effects of global change. The office began formal operation in 1993. formal operation in 1993.


1992: In June of 1992, over 100 1992: In June of 1992, over 100 government leaders, representatives government leaders, representatives from 170 countries, and some 30,000 from 170 countries, and some 30,000 participants met in Rio de Janeiro at participants met in Rio de Janeiro at the U.N. Conference on Environment the U.N. Conference on Environment and Development (UNCED or the and Development (UNCED or the "Earth Summit"). "Earth Summit").


There, an international assembly There, an international assembly formally recognized the need to formally recognized the need to integrate economic development and integrate economic development and environmental protection into the goal environmental protection into the goal of sustainable development. of sustainable development.


1997: In December, 1997, more than 1997: In December, 1997, more than 160 nations met in Kyoto, Japan, to 160 nations met in Kyoto, Japan, to negotiate binding limitations on negotiate binding limitations on greenhouse gases for the developed greenhouse gases for the developed nations, pursuant to the objectives of nations, pursuant to the objectives of the Framework Convention on Climate the Framework Convention on Climate Change of 1992. Change of 1992.


The outcome of the meeting was the The outcome of the meeting was the Kyoto Protocol, in which the developed Kyoto Protocol, in which the developed nations agreed to limit their nations agreed to limit their greenhouse gas emissions, relative to greenhouse gas emissions, relative to the levels emitted in 1990. The United the levels emitted in 1990. The United States agreed to reduce emissions from States agreed to reduce emissions from 1990 levels by 7 percent during the 1990 levels by 7 percent during the period 2008 to 2012. period 2008 to 2012.


1997: In December, 1997, more 1997: In December, 1997, more than 160 nations met in Kyoto, than 160 nations met in Kyoto, Japan, to negotiate binding Japan, to negotiate binding limitations on greenhouse gases for limitations on greenhouse gases for the developed nations, pursuant to the developed nations, pursuant to the objectives of the Framework the objectives of the Framework Convention on Climate Change of Convention on Climate Change of 1992. 1992.


The outcome of the meeting was the The outcome of the meeting was the Kyoto Protocol, in which the developed Kyoto Protocol, in which the developed nations agreed to limit their nations agreed to limit their greenhouse gas emissions, relative to greenhouse gas emissions, relative to the levels emitted in 1990. the levels emitted in 1990. The United States agreed to reduce The United States agreed to reduce emissions from 1990 levels by 7 percent emissions from 1990 levels by 7 percent during the period 2008 to 2012. during the period 2008 to 2012.


Also that year, the United States Senate Also that year, the United States Senate unanimously passed the Hagel-Byrd unanimously passed the Hagel-Byrd Resolution notifying the Clinton Resolution notifying the Clinton Administration that the Senate would not Administration that the Senate would not ratify any treaty that would (a) impose ratify any treaty that would (a) impose mandatory greenhouse gas emissions mandatory greenhouse gas emissions reductions for the United States without reductions for the United States without also imposing such reductions for also imposing such reductions for developing nations, or (b) result in serious developing nations, or (b) result in serious harm to our economy. harm to our economy.


2001: The IPCC released its third 2001: The IPCC released its third assessment report, concluding on the assessment report, concluding on the basis of "new and stronger evidence that basis of "new and stronger evidence that most of the observed warming over the most of the observed warming over the last 50 years is attributable to human last 50 years is attributable to human activities." They also observed that "the activities." They also observed that "the globally averaged surface temperature is globally averaged surface temperature is projected to increase by 1.4 to 5.8 degrees projected to increase by 1.4 to 5.8 degrees Celsius over the period 1990 to 2100." Celsius over the period 1990 to 2100."


The same year, President George The same year, President George W. Bush announced that the United W. Bush announced that the United States would not ratify the Kyoto States would not ratify the Kyoto Protocol. The Protocol is now in Protocol. The Protocol is now in limbo until one of the two crucial limbo until one of the two crucial holdouts — Russia or the United holdouts — Russia or the United States — will ratify the treaty. States — will ratify the treaty.


2003: Senator John McCain (R-2003: Senator John McCain (R-AZ) and Senator Joseph AZ) and Senator Joseph Lieberman (D-CT) co-sponsored Lieberman (D-CT) co-sponsored a proposal for mandatory caps a proposal for mandatory caps on "greenhouse gas" emissions on "greenhouse gas" emissions from utilities and other from utilities and other industries. industries.


Although the proposal was rejected Although the proposal was rejected in the Senate by a margin of 55 to in the Senate by a margin of 55 to 43, it was the Senators' first 43, it was the Senators' first attempt to garner Senate attention attempt to garner Senate attention for the issue of global warming, and for the issue of global warming, and McCain and Lieberman were McCain and Lieberman were encouraged by the support for the encouraged by the support for the measure. measure.

Documents

Human Impact on the Atmosphere. Pollution Thorpe, Gary S., M.S., (2002). Barron’s How to prepare for the AP Environmental Science Advanced Placement Exam