GLOBAL CHANGE TOPIC #7

CLIMATE CHANGE: (previously known as Global Warming)  Involves the Greenhouse Effect: o Greenhouse gases in the troposphere trap heat from the sun to warm the earth

CLIMATE CHANGE: (previously known as Global Warming) Layer of Atmosphere: TROPOSPHERE Type of Radiation: IR (infrared -or- heat) Chemicals Involved: 1.Greenhouse gases (naturally-occurring): H 2 O vapor and clouds CO 2 CH 4 N 2 O 2.Pollutants that behave like greenhouse gases: O 3  NOx Responsible for up to 72% of the greenhouse effect

CLIMATE CHANGE: (previously known as Global Warming) Anthropogenic increases in CH 4 : 1.Cattle (CH 4 ) 2.Rice farms/paddies (CH 4 ) 3.Land fills (CH 4, CO 2 )

CLIMATE CHANGE: (previously known as Global Warming) Environmental Effects of increased surface temperature: 1. Destruction of Arctic habitats 2. Decrease in Arctic’s albedo (reflective) effect 3. Destruction of coast & coastal wetlands (caused by rising sea levels) due to: a.Melting of glacial ice and ice sheets b.Thermal expansion of water 4. Destruction of tundra habitats due to melting of permafrost (also emits CH 4 ) Due to melting of Arctic ice

CLIMATE CHANGE: (previously known as Global Warming) Environmental Effects of increased surface temperature: 5.Drought in some areas – fewer plants, more fires 6.Extreme storms in some areas due to increased water vapor in air 7.Changes in animal migration patterns and agricultural planting zones

CLIMATE CHANGE: (previously known as Global Warming) Human Health Effects of increased temperatures: 1.More diseases that involve insect vectors (insects thrive in warmer climates) 2.Increased heat-stroke and heat-related deaths

CLIMATE CHANGE: (previously known as Global Warming) Causes of Global Warming: (due to anthropogenic increases in greenhouse gases) 1.Motor vehicles (NOx, CO 2, O 3 ) 2.Power plants (NOx, CO 2 ) 3.Cattle (CH 4 ) 4.Rice farms/paddies (CH 4 ) 5.Forest fires (CO 2 ) 6.Deforestation (CO 2 ) 7.Land fills (CH 4, CO 2 ) 8.Agricultural fertilizer (N 2 O)

OZONE DEPLETION  Ozone Depletion (thinning of ozone layer) o Has nothing to do with burning fossil fuels or greenhouse effect!!! o Ozone layer  Acts like a sunscreen  Should keep out 95-99% of UV radiation

CH 19 Ozone Layer ❶ ❷ ❹ ❸ Visible, UV, IR ❷ STRATOSPHERE Similar to troposphere, but less H 2 O, more O 3 Contains ozone layer Filters UV radiation Formed by following photochemical reaction: UVA UVB UVC 5% 1% 3O 2 + UV ↔ 2O 3

Chemical formula: CCl 3 F Created in lab in 1930’s; inexpensive; nonpoisonous; nonflammable; noncorrosive; unreactive in troposphere Takes years to reach stratosphere In 1974, it was discovered that they react w/UV and O 3 in stratosphere – deplete the stratospheric ozone Remain reactive for 100 years Chlorofluorocarbons or CFCs

CFCl 3 CFCl 2 + Cl- Chlorofluorocarbons or CFCs UV ClO + O 2 O3O3 Cl- unstable Other halogens (F-, Br-) behave the same as Cl-

A stronger statement: The greenhouse effect is the warming of the earth due to gases in the troposphere, called greenhouse gases, that trap heat from the sun to warm the earth. Carbon dioxide is a greenhouse gas that is released into the troposphere by the burning of fossil fuels. Fossil fuel use releases carbon dioxide, which causes the greenhouse effect.”

International Treaties KYOTO PROTOCOL (1997) Proposed to cut greenhouse gas emissions to pre-1990 levels by 2012 Includes “cap and trade” and carbon credits Not ratified by U.S. – objection was due to developing countries (China, India) not required to ratify MONTREAL Treaty (1987) Cut CFCs by 35% by 2000 COPENHAGEN Treaty (1992) Accelerate phase-out of CFCs and similar chemicals Ozone layer should return to 1980 levels by 2068; pre-1950 levels by 2108

1.Deepwater Horizon (2010) 2.Kyoto Protocol (1997) 3.Exxon-Valdez (1989) 4.Montreal Treaty (1989) 5.Chernobyl (1986) 6.Bhopal (1984) 7.Love Canal (1978) 8.Endangered Species Act (1973) Important Events

Important Locations A. B. C. D. E. F. G. Iceland Philippines Indonesia Saudi Arabia