Environmental Science Air & Water Quality Issues Your name University of Maine Dept. of…

Environmental Science Interdisciplinary Interdisciplinary Traditional science, politics, social organization, economics, ethics, … Traditional science, politics, social organization, economics, ethics, … Pollution and Policy Pollution and Policy Addressing environmental problems and concerns is not an easy task Addressing environmental problems and concerns is not an easy task Perceptions and opinions vary Perceptions and opinions vary Scientific knowledge and government policy do not always agree Scientific knowledge and government policy do not always agree

Air Quality Global Warming Global Warming Greenhouse Effect Greenhouse Effect 1 o C average temperature rise last century 1 o C average temperature rise last century Ozone Depletion Ozone Depletion Protective layer allows our existence Protective layer allows our existence Primary Air Pollutants Primary Air Pollutants Affects us directly Affects us directly

Warming/Cooling is a Natural Process (Pleistocene Epoch: last 4 million years) ~ 100,000 years: Earth’s climate cycle ~ 100,000 years: Earth’s climate cycle 80-85,000 years: “Ice Age” 80-85,000 years: “Ice Age” 15-20,000 years: warming period 15-20,000 years: warming period We are currently about 18,000 years into Earth’s latest warming period We are currently about 18,000 years into Earth’s latest warming period

Global Warming

Greenhouse Gases Carbon Dioxide, CO 2 Carbon Dioxide, CO 2 Chlorofluorocarbons (CFCs), CCl 3 F Chlorofluorocarbons (CFCs), CCl 3 F Methane, CH 4 Methane, CH 4 Nitrous Oxide, NO x Nitrous Oxide, NO x N 2 + O 2  N 2 + O 2  2NO + O 2  2NO + O 2  2NO (nitrogen oxide) 2NO 2 (nitrogen dioxide)

Carbon Dioxide, CO 2 Most abundant of the greenhouse gases Most abundant of the greenhouse gases Contribution to global warming: 55% Contribution to global warming: 55% Produced naturally Produced naturally Respiration Respiration Volcanic activity Volcanic activity

Volcanic Activity

Carbon Dioxide continued… Most abundant of the greenhouse gases Most abundant of the greenhouse gases Contribution to global warming: 55% Contribution to global warming: 55% Produced naturally Produced naturally Respiration Respiration Volcanic activity Volcanic activity Produced unnaturally Produced unnaturally Waste product of combustion Waste product of combustion Gasoline, coal, oil, natural gas, biomass, … Gasoline, coal, oil, natural gas, biomass, …

Factories

Automobiles

Steady Increase in CO 2 Concentration

CO 2 Sink Plants and trees absorb CO 2, but… Plants and trees absorb CO 2, but… Massive deforestation makes the problem worse Massive deforestation makes the problem worse South American Rain Forests, … South American Rain Forests, …

Chlorofluorocarbons (CFCs) Contribution to global warming: 24% Contribution to global warming: 24% Entirely the result of human activity Entirely the result of human activity Refrigerant gases Refrigerant gases Cleaning solvents Cleaning solvents Propellants in aerosol containers Propellants in aerosol containers 15,000 times more efficient at trapping heat than carbon dioxide 15,000 times more efficient at trapping heat than carbon dioxide

CFCs, continued… Many international efforts since 1987 aimed at reducing CFCs Many international efforts since 1987 aimed at reducing CFCs In 1996, the U.S. stopped producing CFCs In 1996, the U.S. stopped producing CFCs CFC concentrations in the atmosphere have stabilized and are expected to decline CFC concentrations in the atmosphere have stabilized and are expected to decline Many developing nations still produce CFCs Many developing nations still produce CFCs

Methane, CH 4 Contribution to global warming: 15% Contribution to global warming: 15% Biological Sources Biological Sources Several kinds of bacteria Several kinds of bacteria Abundant in wetlands and rice fields Abundant in wetlands and rice fields Stomachs of ruminant animals such as cattle Stomachs of ruminant animals such as cattle

Methane, CH 4 1 billion cows worldwide 1 billion cows worldwide A single cow can produce more than 14 cubic feet of methane each day A single cow can produce more than 14 cubic feet of methane each day

Nitrous Oxide, NO x Contribution to global warming: 6% Contribution to global warming: 6% Primary sources Primary sources Fossil fuels Fossil fuels Fertilizers Fertilizers

Result

Ozone, O 3 Good ozone vs. bad ozone Good ozone vs. bad ozone Ozone layer (good ozone) Ozone layer (good ozone) Stratosphere 8-15 miles up Stratosphere 8-15 miles up Absorbs 99% of damaging UV radiation Absorbs 99% of damaging UV radiation O 3 + UV light  O 2 + O O 3 + UV light  O 2 + O O 2 + O  O 3 O 2 + O  O 3

The Atmosphere

Ozone Depletion Reduction in ozone layer first observed in the 1970s Reduction in ozone layer first observed in the 1970s CFCs are the main culprit CFCs are the main culprit Chlorine radicals strongly react with O 3 Chlorine radicals strongly react with O 3 Cl + O 3  Cl + O 3  And if that’s not bad enough… And if that’s not bad enough… ClO + O  ClO + O  ClO + O 2 Cl + O 2

Bad News about Ozone CFCs destroy ozone and remove atomic oxygen as well (O 3 can’t recombine) CFCs destroy ozone and remove atomic oxygen as well (O 3 can’t recombine) It can take years for CFC molecules to reach the stratosphere! It can take years for CFC molecules to reach the stratosphere! CFC molecules can react and destroy ozone molecules for up to 120 years CFC molecules can react and destroy ozone molecules for up to 120 years Ozone depletion will worsen well into this century before any improvements are seen Ozone depletion will worsen well into this century before any improvements are seen

Primary Air Pollutants Carbon monoxide, CO Carbon monoxide, CO Incomplete burning of fossil fuels Incomplete burning of fossil fuels Single largest source: the automobile Single largest source: the automobile 100 ppm can cause dizziness and headaches 100 ppm can cause dizziness and headaches

Primary Air Pollutants, continued Particulates Particulates Very small pieces of solid material Very small pieces of solid material Particles can accumulate in the lungs Particles can accumulate in the lungs Repeated exposure > serious health effects Repeated exposure > serious health effects Carcinogenic materials Carcinogenic materials

Primary Air Pollutants, continued Nitrous oxide, NO x Nitrous oxide, NO x Primary source: automobile engine Primary source: automobile engine NO x reacts with UV light to form smog NO x reacts with UV light to form smog N 2 + O 2  2NO N 2 + O 2  2NO 2NO + O 2  2NO 2 2NO + O 2  2NO 2 NO 2 + UV light  NO 2 + UV light  O 2 + O  O 3 O 2 + O  O 3 NO + O

Smog Two destructive components of smog Two destructive components of smog Ozone (bad ozone) Ozone (bad ozone) Mutagen Mutagen Destroys chlorophyll in plants Destroys chlorophyll in plants Injures lung tissue Injures lung tissue Peroxyacetyl nitrates Peroxyacetyl nitrates Eye irritants Eye irritants

Smog, continued Smog is a serious problem in many large cities Smog is a serious problem in many large cities Especially those cities ringed by mountains Especially those cities ringed by mountains

So why does any of this matter to you?

Because we are not immune

The northeast is this nation’s tailpipe

Ground-level Ozone

Ozone isn’t the only pollutant flowing through the northeast

Water Quality Issues Acid Rain Acid Rain Air pollutants react with moisture in atmosphere Air pollutants react with moisture in atmosphere Sulfur dioxide and nitrogen dioxide Sulfur dioxide and nitrogen dioxide SO 2 + H 2 O + ½O 2  SO 2 + H 2 O + ½O 2  2NO 2 + H 2 O  HNO 2 + 2NO 2 + H 2 O  HNO 2 + H 2 SO 4 (Sulfuric acid) HNO 3 (Nitric acid)

Acid-base pH scale pH 7.0 ~ neutral pH 7.0 ~ neutral pH 5.6 ~ acid rain (25 times more acidic than pure water) pH 5.6 ~ acid rain (25 times more acidic than pure water) pH 3.0 ~ highly acid pH 3.0 ~ highly acid

Lakes become acidic Healthy lakes have a pH over 6.0 Healthy lakes have a pH over 6.0 At a pH of 5.5, many desirable species of fish have been eliminated At a pH of 5.5, many desirable species of fish have been eliminated Birth defects common Birth defects common

Trees and vegetation decline

Limestone deteriorates

You Can’t Hide From Acid Rain The northeast is highly prone to severe acid rain The northeast is highly prone to severe acid rain pH 3.0 to 4.0 not uncommon pH 3.0 to 4.0 not uncommon pH 2.3 worst recorded (1000 times more acidic than pure water) pH 2.3 worst recorded (1000 times more acidic than pure water)

Other Water Quality Issues Oil Spills Oil Spills

Thank you The End