Climate Change and Human-Induced Global Warming

1. Climate Change and Human-Induced Global Warming

2. The Greenhouse Effect • A normal climatic warming effect caused by permitting incoming solar radiation but inhibiting outgoing terrestrial radiation. • Three gases are the primary cause: • Carbon Dioxide (CO2) • Methane (CH4) • Water Vapor (H2O) • The effect is possible because outgoing earth radiation is of much longer wavelengths than incoming insolation and it gets caught or trapped in the atmosphere.

3. The Greenhouse Effect • Keeps Earth’s average temperature 35ºC warmer (15ºC now, -20 ºC otherwise) • Human role? ‘A heated debate’ Venus 480ºC thick carbon dioxide Mars -62 ºC little carbon dioxide

4. The Carbon Cycle

5. b

6. Now to the most ominous symptom of all: a fever that’s rising fast. The 10 hottest years on record in order: 2010 2005 1998 2003 2002 2009 2006 2007 2004 2001 Source: National Climate Data Center (NOAA). 2011. Global Surface Temperature Anomalies. http://www.ncdc.noaa.gov/

7. Note that very recent rate of increase greatly exceeds anything in last 1000 years. Source: International Panel on Climate Change (IPCC), 2001

8. Note correlations in the data.

9. 650,000 years of climate and CO2

10. The yellow arrow indicates when the first agricultural towns were built. The Earth’s temperature was remarkably stable over the 10,000 years. Source: Intergovermental Arctic Climate Impact Assessment (ACIA). 2004. http://www.acia.uaf.edu/pages/scientific.html

11. Changes in Solar Radiation Milankovitch Cycles explain much (60%+) of the changes: • 21,000 year cycle: perihelion shifts throughout the year • 41,000 year cycle: +/- 1.5° change in Earth's tilt • 100,000 year cycle: Orbital eccentricity of the elliptical orbit of the Earth The most recent ice age lasted 100, 000 years. We are currently in an interglacial period (Holocene).

12. We continue to increase our consumption of fossil fuels. Carbon dioxide levels are still rising in her lungs. Source: Worldwatch Institute. 2007. Vital Signs 2007-2008. Source: U.S. Global Change Research Program. 2009. Global Climate Change Impacts in the U.S. www.globalchange.gov.

13. How much warmer will it get? Source: U.S. Global Change Research Program. 2009. Global Climate Change Impacts in the U.S. www.globalchange.gov.

15. Climate models suggest that the changes are just beginning now and will accelerate rapidly.

16. Global Warming Effects Human-induced rise in CO2 levels is already leading to increased greenhouse forcing and unnatural warming of atmosphere. • Likely future effects: • Increased storminess, more droughts, more intense downpours • More intense hurricanes and, possibly, tornadoes • Rising sea level (.36 to 2.5 feet)in 100 years (IPCC, 2007)* • Loss of farmable land, especially in arid regions • Extinction of thousands of species • Loss of nearly all coral reef • Increased range of tropical diseases • Flooding of low-lying coastal regions * IPCC estimate does not include Greenland Ice Sheet

17. “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level. “ IPCC Report, 2007

18. So is sea level rise happening? How much? Sea level rise is not well understood. In their 2001 report, the Intergovernmental Panel on Climate Change stated that global warming should cause sea levels to rise 0.11 to 0.77 meters (0.36 to 2.5 feet) by 2100. When added to storm surges and high tides, these small changes may have large effects. Moreover, because Greenland’s ice sheet is not well understood it was not included in these estimates. It represents much of the ice on Earth. Source: UN IPCC, 2001 Source: UN IPCC, 2001

19. Global Warming? Climate change will lead to more chaotic and unpredictable weather:"Climate change will bring warm, wet weather, which will encourage plants to grow, followed by long periods of drought, during which they will burn." - Meinrat Andreae, Max Planck Institute for Chemistry, August 2001.

20. She is already suffering frequent hot flashes, dehydration, sweats, and chills. Hurricane Katrina, 2005

21. Glaciers are melting much faster than predicted.

22. Extreme weather events are becoming more common; severe droughts, floods, fires, heat waves, blizzards are all increasing in frequency. Sources: Min, S.-K. et al. Nature470, 378-381 (2011); Pall, P. et al. Nature470, 382-385 (2011); Stott, P. A. et al. Nature432, 610-614  Lake Hindmarsh, Victoria, Australia. May, 2007

23. Queensland, Australia. January, 2011

25. Difference in average temperature(2000, 2001, 2002 and 2004) from 2003, covering the date range of July 20 - August 20. 40,000 – 50,000 people died as a result of the record heat wave that scorched Europe in August 2003. It was the hottest summer in Europe in 1500 years. France, 2003 Source: Larsen, J. Earth Policy Institute. 2006. Setting the Record Straight: More than 52,000 Europeans Died from Heat in Summer 2003. http://www.earth-policy.org/index.php?/plan_b_updates/2006/update56

26. One degree of temperature change in the last 100 years has led to four times as many fires in the American West. Station Fire, 2009

28. Surface water will decrease in the U.S. Southwest. Source: U.S. Global Change Research Program. 2009. Global Climate Change Impacts in the U.S. www.globalchange.gov.

29. Current and future trends and impacts • Scientific evidence that climate has changed since industrialization is now overwhelming and indisputable. • Intergovernmental Panel on Climate Change (IPCC) • An international panel of scientists and government officials established in 1988 • The most thoroughly reviewed and widely accepted synthesis of scientific information on climate change • Has issued a series of reports on climate change

30. IPCC report: Continued temperature increases • The IPCC 2007 report concludes that average surface temperatures on earth have been rising since 1906, mostly in the last few decades. • At the end of the 21st century, temperatures will be 1.8-4.0° C (3.2-7.2 ° F) higher than today.

31. Global temperature change will vary • Sea surface temperatures will also increase as oceans absorb more heat. • May not have more storms, but storms will be stronger and longer

32. Projected changes in precipitation • High latitudes = increased precipitation • Low and middle latitudes = decreased precipitation will worsen water shortages in developing countries

33. Melting snow and ice • Mountaintop glaciers are disappearing • In Glacier National Park, only 27 of 150 glaciers remain but will be gone by 2030. • Reducing summertime water supplies • The Arctic and Greenland ice sheets are rapidly melting. • In Antarctica, ice shelves the size of Rhode Island have disintegrated. • As ice melts, darker, less-reflective surfaces are exposed and absorb more sunlight, causing more melting.

34. Rising sea levels • As glaciers and ice melt, increased water will flow into the oceans. • As oceans warm, they expand. • Leads to beach erosion, coastal floods, and salt water intrusion into aquifers

35. Climate change affects ecosystems • For example, consider threats to coral reefs: • Warmer waters (coral bleaching) • Ocean chemistry is becoming more acidic, impairing coral growth. • Will greatly reduce biodiversity. • Increased precipitation will increase erosion and flooding, which will pollute aquatic systems. • Ecosystem goods and services will decrease.

36. Climate change exerts societal impacts • Human society is beginning to feel the impacts of climate change. • Forestry: • Increased insect and disease outbreaks (e.g. bark beetles) • Invasive species (mosquitoes) • Forest fires (especially in rainforests) • Agriculture: • Droughts, floods, • Decreased yields, worsened hunger

37. Climate change affects economics and health • Economics: the costs will outweigh benefits • Widen the gap between rich and poor • Could cost 5-20% of GDP by 2200 • Poor nations will lose more than rich ones. • Investing 1% of GDP now could help us avoid these costs. • Health: heat waves and stress can cause death, respiratory ailments, expansion of tropical diseases, disease and sanitation problems, drowning, hunger-related ailments

38. Impacts will vary regionally Today, temperature changes are greatest in the Arctic. • Ice sheets are melting. • Sea ice is thinning. • Storms are increasing. • Polar bears are starving. • Melting permafrost is destabilizing buildings.

39. U.S. Global Change Research Program (2008) Highlighted past effects and predicted future impacts of climate change in U.S.

40. Are we responsible for climate change? • The IPCC 2007 report concluded that it is more than 90% likely that most global warming is due to humans. • In 2005, the national academies of 11 nations issued a joint statement urging political leaders to take action. By 2010 more than 30 countries National Academies of Science had such statements. • The debate on climate change is fanned and funded by corporate and oil industry skeptics. The science is clear and unequivocal.

41. Shall we pursue mitigation or adaptation? • Mitigation: pursue actions that reduce greenhouse gas emissions to lessen severity of future climate change • Renewable energy, efficiency, farm practices to protect soil integrity, preventing deforestation • Adaptation: accept climate change is happening and pursue strategies to minimize its impacts • Uses technology and engineering, adjusting farming to cope with droughts, etc. • Criticized as sidestepping

42. Electricity generation • Tied with agribusiness as the largest source of U.S. greenhouse gas (GHG) emissions • Two ways to reduce fossil fuel use: conservation and efficiency • Arise from technology and individual choices • Removing or storing CO2 somewhere (underground?) – “Capture and Sequestration “ • Use renewable fuels Navajo Generating Station

43. Transportation • Ways to help: • Make vehicles more fuel-efficient, hybrid cars • Drive less • Public transportation is the most effective way to conserve energy, reduce pollution. • Live closer to your workplace, so you can bike or walk. • Design cities and workplaces to be more friendly to pedestrian and bicycle traffic.

44. Conventional cars are inefficient The typical automobile is highly inefficient.

45. The Politics of Mitigation • UN Framework Convention on Climate Change (FCCC): outlined a plan for reducing greenhouse gas emissions to 1990 levels by the year 2000 through a voluntary, nation-by-nation approach • By the late 1990s, it was clear that the voluntary approach would not succeed. • Most developed nations did not voluntarily cut emissions. • Latest meeting agreed to aim for no more than 2O Celsius temperature increase and to aid developing countries. • The Kyoto Protocol mandates that, between 2008-2012, signatory nations must reduce emissions of six greenhouse gases to levels below those of 1990. • This treaty took effect in 2005, after Russia became the 127th nation to ratify it. • The U.S. and Australia are the only industrialized nations that have not ratified the treaty.

46. Others are advancing climate change policy • U.S. state and local governments are advancing policies to limit greenhouse emissions. • Mayors from 850 cities agreed to pursue policies to “meet or beat” Kyoto Protocol guidelines. • California is determined to cut greenhouse gas emissions 25% by the year 2020 (Assembly Bill 32). • 10 northeastern states set up a cap-and-trade program for carbon emissions from power plants.

47. Market mechanisms could address climate change • Carbon taxes replace income taxes. • A cap and trade emissions trading program • Each state decides who needs to participate. • Each sets a cap on allowable carbon emissions. • Each emissions source gets one permit. • The source can buy or sell permits. • Any source emitting more than its permitted amount will face penalties.

48. Global Warming “Indulgences?” • Emissions trading programs allow participants to buy carbon offsets. • Carbon offset: a voluntary payment to enable another entity to reduce emissions that one is unable to reduce oneself • Popular among utilities, businesses, universities, governments, and individuals trying to achieve carbon-neutrality, where no net carbon is emitted • A simple, convenient (but expensive) way to reduce emissions without changing habits • Carbon offsets fall short. • Needs oversight to make sure that the offset money accomplishes what it is intended for

49. Top 10 solutions to climate change

50. Conclusion • Many factors influence Earth’s climate. • Human activities play a major role. • Climate change is well underway. • Further emissions will cause severe impacts. • More and more scientists and policymakers are urging immediate action. • Reducing emissions, and mitigating and adapting to a changing climate, represents the foremost challenge for our society.