Chapter 21 Global Climate Change

Climate Change Terminology  Greenhouse Gas  Gas that absorbs infrared radiation  Positive Feedback  Change in some condition triggers a response that intensifies the changed condition  Infrared Radiation  Radiation that has a wavelength that is longer than that of visible light, but shorter than that of radio waves  Greenhouse Effect  Increase of heat in a system where energy enters (often as light), is absorbed as heat, and released sometime later

Introduction to Climate Change  "Scientific evidence for warming of the climate system is unequivocal." - Intergovernmental Panel on Climate Change

Evidence of Climate Change  Spring in N. hemisphere now begins 6 days earlier

Evidence of Climate Change   Sea level rise

Evidence of Climate Change   Global temperature rise

Evidence of Climate Change   Warming oceans

Evidence of Climate Change   Shrinking ice sheets   The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA show Greenland lost km 3 /year between , while Antarctica lost about 152 km 3 of ice between Flowing meltwater from the Greenland ice sheet

Evidence of Climate Change   Declining Arctic sea ice   Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. 99

Evidence of Climate Change   Glacial retreat   Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.1010

Evidence of Climate Change   Extreme events   The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since The U.S. has also witnessed increasing numbers of intense rainfall events.1111

Evidence of Climate Change   Ocean acidification   The carbon dioxide content of the Earth’s oceans has been increasing since 1750, and is currently increasing about 2 billion tons/year. This has increased ocean acidity by about 30%. 1212

Introduction to Climate Change: Mean Annual Global Temperature 1960–2007

Causes of Climate Change  Greenhouse gas concentrations increasing

Causes of Climate Change  Increased concentration of CO 2  Burning fossil fuels in cars, industry and homes  Deforestation  Burning of forests

Greenhouse Effect

Pollutants That Cool the Atmosphere  Atmospheric Aerosols  Both human and natural sources  Tiny particles that remain in troposphere for weeks or months  Often contain sulfur  Complicates models of climate change

Climate Models  Climate affected by:  winds, clouds, ocean currents, and albedo  Advanced models can project future warming events  Models have limitations

Effects of Global Climate Change  Wildfire in California

Effects of Global Climate Change: 1. Melting Ice and Rising Sea Levels Sea level rise caused in 2 ways 1. Thermal Expansion 2. Melting of land ice  Melting has positive feedback  Increased melting decreases ice, which decreases albedo leading to further warming

Glacier National Park Melting Ice and Rising Sea Levels

Impacts in Fragile Areas  Eskimo Inuit  Climate change isaltering their existence  Wildlife displaced  Reduced snow cover and shorter river ice seasons  Thawing of permafrost (right)  Tuvalu- threatened by permanent flooding on their island

Effects of Global Climate Change: 2. Changing Precipitation Patterns  Some areas will get more water, some areas will have greater droughts

Effects of Global Climate Change: 3. Effects on Organisms  Zooplankton in parts of CA have decreased by 80% since 1951  Effecting entire food chain  Decline in krill around Antarctica  Species have shifted their geographic range  Migrating birds are returning to summer homes earlier

Effects on Organisms: Coral Reefs  Coral reefs can be bleached (right) due to increase in water temperature  Affects coral symbiotes and makes them more susceptible to diseases

Effect on Organisms: Vegetation

4. Effects on Human Health  Increased number of heat-related illnesses and deaths

5. Effects on Agriculture  Difficult to anticipate  Productivity will increase in some areas and decrease in others  Rise in sea level will inundate farmland  Effect on pests is unknown  Warmer temperatures will decrease soil moisture- requiring more irrigation  Location where certain crops can be grown may change

International Implications of Climate Change  Developed vs. Developing countries  Differing self- interests  Differing ability to meet the challenges of climate change

Dealing with Global Climate Change Two ways to manage climate change 1. Mitigation: Limiting greenhouse gas emissions to moderate global climate change 2. Adaptation: Learning to live with environmental changes and societal consequences brought about by global climate change

Relationship Between Mitigation and Adaptation

Dealing with Global Climate Change: Mitigation  Locate/invent alternative fuels to fossil fuels  Increase efficiency of cars and trucks  Carbon Capture and Storage  Plant and Maintain trees to naturally sequester carbon

Dealing with Global Climate Change: Adaptation  Rising sea levels and coastal populations  Move inland  Construct dikes and levees  Adapt to shifting agricultural zones  NYC sewer line

International Efforts to Reduce Greenhouse Gas Emission  Kyoto Protocol  Legally binding  Provides rules on reducing greenhouse gases  US and Australia have not sign it - it will be difficult to implement without US backing

  Chapter 21: Global Climate Change Climate Crisis Network   Goddard Institute for Space Studies: Surface Temperature Analysis   United Nations Intergovernmental Panel on Climate Change   US Global Change Research Program   Pew Center on Global Climate Change   World View of Global Warming - The Photographic Documentation of Climate Change