What is global warming? "Global warming" refers to the rise in the Earth's temperature resulting from an increase in heat-trapping gases in the atmosphere.
What is causing global warming? • The Greenhouse Effect: addition of large amounts of heat-trapping gases, such as CO2 to the atmosphere due to burning of fossil fuels • Deforestation: mainly in the tropics, and other land-use changes.
Is global warming already happening? • Yes. The IPCC concluded in its Third Assessment Report, "An increasing body of observations gives a collective picture of a warming world and other changes in the climate system."
Examples of observed climatic changes • Increase in global average surface temperature of about 1°F in the 20th century • Decrease of snow cover and sea ice extent and the retreat of mountain glaciers in the latter half of the 20th century
Examples of observed climatic changes • Rise in global average sea level and the increase in ocean water temperatures • Likely increase in average precipitation over the middle and high latitudes of the Northern Hemisphere, and over tropical land areas • Increase in the frequency of extreme precipitation events in some regions of the world
Examples of observed physical and ecological changes • Thawing of permafrost • Lengthening of the growing season in middle and high latitudes • Poleward and upward shift of plant and animal ranges • Decline of some plant and animal species
Examples of observed physical and ecological changes • Earlier flowering of trees • Earlier emergence of insects • Earlier egg-laying in birds
Is there anything we can do about global warming? Yes! The most important action we can take to slow global warming is to reduce emissions of heat-trapping gases.
What can the government do to reduce greenhouse gases? • Increasing energy efficiency standards • Encouraging the use of renewable energy sources (such as wind and solar power) • Eliminating subsidies that encourage the use of coal and oil by making them artificially cheap • Protecting and restoring forests, which serve as important storehouses of carbon
What can individuals do to reduce greenhouse gases? • Driving less and driving more fuel-efficient and less-polluting cars • Using energy-efficient appliances • Insulating homes • Using less electricity in general