Section 16.2- Climate Change According to NASA’s Goddard Institute for Space Studies, 2009 tied for second warmest year on record, just behind 2005. The decade spanning 2000–2009 was the warmest on record. 1

Global Warming Greenhouse effect- natural phenomenon of the earth’s atmosphere to act like a greenhouse. Good Thing= why we are not a frozen planet Greenhouse Gases (water vapor, CO2, methane, nitrous oxide, and CFCs) absorb the heat from sunlight and radiate it back toward the lower atmosphere.

Greenhouse Gases

Organisms (especially plants) need the effects of this warming. Problem = too much of a good thing  too much heat is being absorbed by the atmosphere, causing severe weather pattern changes

The Role of CO2 As the level of CO2 increases, temperature is shown to increase Humans directly add a large amount of CO2 into the atmosphere by burning fossil fuels

Evidence of a Warming Earth Rising global surface temperatures Changes in precipitation patterns Melting ice (glaciers, polar ice) Rising sea level Both photos show Sperry Glacier in Montana’s Glacier National Park. Top: 1913 Bottom: 2008 6

Consequences The earth is increasing its Global Temperature (+0.6 °C = 2 °F) since 1880. Melting of the ice caps Migrating animals change habits Crops die due to drought

More storms- storms are more intense People die because it’s too hot lack of water Changing climates Difficult for plants to adapt Warmer oceans Rising sea levels Increased ocean acidity

Studying Climate Change Direct measurement is used to study today’s climate. Proxy indicators, such as patterns in tree rings, give clues about past climates. Models are used to make predictions about future climates. Cross-section of a tree trunk 9