Composition of Earth’s Atmosphere Nitrogen: 78% Oxygen: 21% Argon: 1% Carbon Dioxide: .038% Water Vapor: 0 - 4% He, H2, O3, etc… trace amounts

Atmospheric pressure (millibars) Altitude (kilometers) Earth’s Atmosphere Atmospheric pressure (millibars) 200 400 600 800 1,000 120 75 Temperature 110 Pressure 65 100 Thermosphere 90 Mesopause 55 Heating via ozone 80 Mesosphere 45 70 60 Stratopause Altitude (kilometers) Altitude (miles) 35 50 Stratosphere 40 25 30 Tropopause 15 Ozone “layer” 20 Heating from the earth 10 5 Troposphere –80 –40 40 80 120 Pressure = 1,000 millibars at ground level (Sea Level) Temperature (˚C) Fig. 15-2, p. 347

Distinctions … weather and climate global warming and the greenhouse effect

Major and Minor Greenhouse Gases H2O - water vapor CO2 - carbon dioxide CH4 - methane N2O – Nitrous Oxide – Laughing Gas CFC’s

Greenhouse Gases and Sources Water vapor- evaporation (from Earth’s natural water cycle) Carbon Dioxide (CO2)- burning fossil fuels and plant matter, deforestation, volcanic eruptions Methane (CH4)- decomposition/decay, livestock waste, decomposing waste in landfills. Nitrous oxide (N2O)- fertilizer production, burning fossil fuels and wood, agricultural soil processes (nitrification and denitrification) Synthetic gases (e.g., fluorinated gases, CFCs)- industrial processes, manufacturing

Average Global Temperature over the Past 900,000 Years 17 16 15 14 Average surface temperature (°C) 13 12 11 10 9 900 800 700 600 500 400 300 200 100 Present Thousands of years ago Fig. 16-2a, p. 369

Temperature Changes Over Past 22,000 Years Agriculture established 1 –1 Average temperature over past 10,000 years = 15°C (59°F) Temperature change (°C) – 2 End of last ice age – 3 – 4 – 5 20,000 10,000 2,000 1,000 200 100 Now Years ago Fig. 16-2b, p. 369

Temperature Changes Over Past 1,000 Years 1.0 0.5 0.0 Temperature change (°C) –0.5 –1.0 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101 Year Fig. 16-2c, p. 369

Average Global Temperature Over Past 130 Years 15.0 14.8 14.6 14.4 Average surface temperature (°C) 14.2 14.0 13.8 13.6 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year Fig. 16-2d, p. 369

Global Climate Change

Changing Carbon Dioxide Levels 1988 - 350 ppm 2010 - 384 ppm Pre-Industrial - 284 ppm

Ice Cores: Records of Past Climates Fig. 16-3, p. 369

Increases in Average Atmospheric Carbon Dioxide Since 1860 410 360 Parts per million 310 260 1800 1900 2000 2100 Year Carbon dioxide (CO2) Fig. 16-5a, p. 371

Rising Carbon Dioxide Levels

Atmospheric Carbon Dioxide and Global Temperatures 380 360 340 320 300 Concentration of carbon dioxide in the atmosphere (ppm) 280 Carbon dioxide 260 240 +2.5 220 200 Variation of temperature (˚C) from current level –2.5 180 –5.0 –7.5 Temperature change End of last ice age –10.0 160 120 80 40 Thousands of years before present Fig. 16-4, p. 370

IPCC Intergovernmental Panel on Climate Change 2500 scientists release periodic reports on the state of the climate mathematical models study interactions among atmospheric conditions and then run these models on supercomputers to predict future climate conditions 2.5 – 3.5 degree (celcius) increase this century

Climate Change and Human Activities

Complicating Factors ocean storage of CO2 cloud cover aerosols and particulates forests methane

Shallow and Deep Ocean Currents Fig. 16-9, p. 374 20

Possible Effects of a Warmer Climate Winners and Losers

heat waves fires droughts

Arctic and Antarctic Ice Loss Melting of Mountain Glaciers

Shrinking Arctic Sea Ice (1979-2003) Fig. 16-6, p. 372 24

extreme weather events

Rising Sea Levels Fig. 16-12, p. 377 26

Loss of Biodiversity

spread of tropical diseases

Human Refugees

Challenges of Dealing with Climate Change validity of the science human cause global issue economics

Solutions

energy efficiency

Renewable Energy

Carbon Sequestration Fig. 16-14, p. 380 Tanker delivers CO2 from plant to rig Oil rig Coal power plant Tree plantation CO2 is pumped down from rig for deep ocean disposal Abandoned oil field Crop field Switchgrass CO2 is pumped down to reservoir through abandoned oil field Spent oil reservoir is used for CO2 deposit = CO2 deposit = CO2 pumping Fig. 16-14, p. 380 34

Solutions to Global Warming Prevention Cleanup Cut fossil fuel use (especially coal) Remove CO2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO2 by planting trees Improve energy efficiency Shift to renewable energy resources Sequester CO2 deep underground Transfer energy efficiency and renewable energy technologies to developing countries Sequester CO2 in soil by using no-till cultivation and taking crop land out of production Reduce deforestation Sequester CO2 in the deep ocean Use more sustainable agriculture Repair leaky natural gas pipelines and facilities Limit urban sprawl Reduce poverty Use feeds that reduce CH4 emissions by belching cows Slow population growth Fig. 16-13, p. 379 35

Preparing for Climate Changes Connect wildlife reserves with corridors Move hazardous material storage tanks away from coast Expand existing wildlife reserves toward poles Stockpile 1- to 5-year supply of key foods Prohibit new construction on low-lying coastal areas or build houses on stilts Develop crops that need less water Waste less water Move people away from low-lying coastal areas Fig. 16-16, p. 382 36