© 2011 Pearson Education, Inc. Current and Future Trends and Impacts AP Environmental Science Mr. Grant Lesson 50

© 2011 Pearson Education, Inc. Objectives: Define the term Intergovernmental Panel on Climate Change (IPCC). Outline current and future trends and impacts of global climate change.

© 2011 Pearson Education, Inc. Intergovernmental Panel on Climate Change (IPCC): An international panel of climate scientists and government officials established in 1988by the United Nations Environment Programme and the World Meteorological Organization. The IPCC’s mission is to assess and synthesize scientific research on global climate change and to offer guidance to the world’s policymakers. The IPCC’s Fourth Assessment Report summarizes current and projected future global trends in climate, and represents the consensus of climate scientists around the world. Define the term Intergovernmental Panel on Climate Change (IPCC).

© 2011 Pearson Education, Inc. Outline current and future trends and impacts of global climate change. The Intergovernmental Panel on Climate Change (IPCC) synthesizes current climate research, and its periodic reports represent the consensus of the scientific community. Temperatures on the Earth have warmed by an average of 0.74 degrees C (1.33 degrees F) over the past century and are predicted to rise degrees C ( degrees F) over the next century. Changes in precipitation vary by region. Melting glaciers will diminish water supplies, and melting ice sheets will add to sea level rise.

© 2011 Pearson Education, Inc. Outline current and future trends and impacts of global climate change. Sea level has risen an average of 17cm (7in) over the past century. Other impacts include ocean acidification; extreme weather events; effects on organisms and ecosystems; and impacts on agriculture, forestry and health, and economics. Climate change and its impacts will vary regionally. Despite some remaining uncertainties, the scientific community feels that evidence for human’s role in influencing climate is strong enough to justify taking action to reduce greenhouse emissions.

© 2011 Pearson Education, Inc. The IPCC’s fourth assessment report (2007) The IPCC reports on the synthesis of scientific information concerning climate change -Global consensus of scientific climate research -Summarized thousands of studies Documented observed trends in surface temperature, precipitation patterns, snow and ice cover, sea levels, storm intensity, etc. Predicted impacts of current and future climate change on wildlife, ecosystems, and human societies Discussed strategies to pursue in response to climate change

© 2011 Pearson Education, Inc. The IPCC’s fourth assessment report (2007)

© 2011 Pearson Education, Inc. Temperatures continue to increase Average surface temperatures increased 0.74 °C since Most of the increase occurred in the last few decades -Extremely hot days have increased -The 16 warmest years on record have been since 1990

© 2011 Pearson Education, Inc. The future will be hotter In the next 20 years, temperatures will rise 0.4 °C At the end of the 21st century, temperatures will be 1.8– 4.0 °C higher than today’s -We will have unusually hot days and heat waves Polar areas will have the most intense warming Sea surface temperatures will rise Hurricanes and tropical storms will increase -In power and duration

© 2011 Pearson Education, Inc. Temperatures will rise globally Projected increases in surface temperature for 2090–2099 relative to 1980–1999

© 2011 Pearson Education, Inc. Precipitation is changing, too Some regions are receiving more precipitation than usual, and others are receiving less Droughts have become more frequent and severe -Harming agriculture, promoting soil erosion, reducing water supplies, and triggering fires Heavy rains contribute to flooding -Killing people, destroying homes, and inflicting billions of dollars in damage

© 2011 Pearson Education, Inc. Projected changes in precipitation Precipitation will increase at high latitudes and decrease at low and middle latitudes

© 2011 Pearson Education, Inc. Melting snow and ice Mountaintop glaciers are disappearing -Glaciers on tropical mountaintops have disappeared -The remaining 26 of 150 glaciers in Glacier National Park will be gone by 2020 or Reducing summertime water supplies Melting of Greenland’s Arctic ice sheet is accelerating Warmer water is melting Antarctic coastal ice shelves -Interior snow is increasing due to more precipitation Melting ice exposes darker, less-reflective surfaces, which absorb more sunlight, causing more melting

© 2011 Pearson Education, Inc. Worldwide, glaciers are melting rapidly Nations are rushing to exploit underwater oil and mineral resources made available by newly opened shipping lanes Permafrost (permanently frozen ground) is thawing -Destabilizing soil, buildings, etc. and releasing methane

© 2011 Pearson Education, Inc. Rising sea levels Runoff from melting glaciers and ice will cause sea levels to rise As oceans warm, they expand -Leading to beach erosion, coastal floods, and intrusion of salt water into aquifers

© 2011 Pearson Education, Inc. Coastal areas will flood Storm surge = temporary, localized rise in sea level -Caused by the high tides and winds of storms Cities will be flooded -53% of people in the U.S. live in coastal areas An earthquake caused the 2004 tsunami (tidal wave) that killed 100 Maldives residents and caused $470 million in damages

© 2011 Pearson Education, Inc. Rising sea levels will devastate coasts 1 million acres of Louisiana’s wetlands are gone -Rising sea levels eat away vegetation -Dams upriver decrease siltation -Pollution from the Deepwater Horizon Millions of people will be displaced from coastal areas

© 2011 Pearson Education, Inc. Coral reefs are threatened Coral reefs are habitat for food fish -Snorkeling and scuba diving sites for tourism Warmer waters contribute to coral bleaching -Which kills corals Increased CO 2 is acidifying the ocean -Organisms can’t build their exoskeletons Oceans have already decreased by 0.1 pH unit -Enough to kill most coral reefs

© 2011 Pearson Education, Inc. Climate change affects organisms and ecosystems Organisms are adapted to their environments -They are affected when those environments change Global warming modifies temperature-dependent phenomena (e.g., timing of migration, breeding) Animals and plants will move toward the poles or upward in elevation -20–30% of species will be threatened with extinction -Rare species will be pushed out of preserves Droughts, fire, and disease will decrease plant growth -Fewer plants means more CO 2 in the atmosphere

© 2011 Pearson Education, Inc. Animals and plants have nowhere to go Animals and plants adopted to montane environments will be forced uphill until there is no place to go

© 2011 Pearson Education, Inc. Climate change affects people Societies are feeling the impacts of climate change Agriculture: shortened growing seasons, decreased production, crops more susceptible to droughts -Increasing hunger Forestry: increased fires, invasive species -Insect and disease outbreaks Health: heat waves and stress can cause death -Respiratory ailments, expansion of tropical diseases -Disease and sanitation problems from flooding -Drowning from storms

© 2011 Pearson Education, Inc. Heat waves will increase

© 2011 Pearson Education, Inc. Climate change affects economics Costs will outweigh benefits of climate change It will widen the gap between rich and poor -Those with less wealth and technology will suffer most External costs of damages will be $10–350/ton of carbon It will cost 1–5% GDP on average globally -Poor nations will lose more than rich ones The Stern Review predicts it will cost 5–20% of GDP by Investing 1% of GDP now could avoid these costs

© 2011 Pearson Education, Inc. Impacts will vary regionally Where we live will determine how we experience the impacts of climate change Temperature changes have been greatest in the Arctic -Melting ice sheets, thinning ice, increasing storms, etc. -Harder for people and polar bears to hunt U.S. temperatures will continue rising -Plant communities will shift north and upward -More frequent extreme weather events The southern U.S. will get drier, the northern wetter -Sea levels will rise and may be worse in the East

© 2011 Pearson Education, Inc. Impacts of climate change The Arctic has suffered the most so far U.S. temperatures will continue to rise

© 2011 Pearson Education, Inc. Impacts of climate change will vary

© 2011 Pearson Education, Inc. The U.S. Global Change Research Program In 2009, scientists reported and predicted: -Temperature increases -Worse droughts and flooding -Decreased crop yields -Water shortages -Health problems and diseases -Higher sea levels, beach erosion, destroyed wetlands -Drought, fire, and pests will change forests -More grasslands and deserts, fewer forests -Undermined Alaskan buildings and roads

© 2011 Pearson Education, Inc. Predictions from two climate models By 2050, Illinois will have a climate like Missouri’s By 2090, it will have a climate like Louisiana’s

© 2011 Pearson Education, Inc. Causes and consequences of climate change

© 2011 Pearson Education, Inc. Are we responsible for climate change? Scientists agree that increased greenhouse gases are causing global warming -Burning fossil fuels is increasing greenhouse gases In 2005, scientists from 11 nations issued a joint statement urging political leaders to take action There is a broad and clear scientific consensus that climate change is a pressing issue -But many people deny what is happening People will admit the climate is changing -But doubt we are the cause

© 2011 Pearson Education, Inc. The debate over climate change is over Conservative think tanks and industry-sponsored scientists cast doubt on the scientific consensus The news media tries to present two sides to an issue -But the sides’ arguments are not equally supported by evidence Most Americans accept that fossil fuel consumption is changing the planet Al Gore’s An Inconvenient Truth helped turn the tide -People who disliked his politics rejected his message

© 2011 Pearson Education, Inc. “Climategate” In 2009, a hacker illegally broke into a university’s computer in the U.K. Private s seemed to show questionable behavior by a few scientists in using data Climate deniers accused the entire scientific establishment of wrongdoing and conspiracy -The story was widely told in the news Investigations showed no evidence of wrongdoing -Media accounts misrepresented the contents These hacked s do not call into question the vast array of results by thousands of scientists over decades