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Beckeredits chapter13climatechange

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Beckeredits chapter13climatechange

  1. 1. Module 13
  2. 2. Why Should You Care About Climate Change? For approx. 10,000 years climate fairly stable (maybe) - Since 1980 temperatures rising - Climate change - 2,500 top scientists, 29,000 data sets - Century of rapid climate change - Likely due to burning of fossil fuels/deforestation/cement production - Climate change will affect other things - Shifting water availability - Heat waves - Food production - Extinctions
  3. 3. Figure 13.1 p350 Two possible consequences of projected climate change during this century are (a) crop losses from excessive heat and lack of water in some areas and (b) prolonged and heavy flooding in other regions such as this area of Thailand that suffered heavy rains in 2011.
  4. 4. What Do You Need to Know? Weather and Climate Weather and climate - Weather is short-term - Easy to recognize - Climate is average during seasons - Requires long-term records - Single hot summers or single cold winters do not predict climate change
  5. 5. The Earth’s Major Climate Zones Earth’s climate into zones - Differences in average temperature and precipitation - Tropical - Temperate - Polar - Heat/sunlight and moisture distributed unevenly - Unevenness/Gradient causes movement - Ocean currents/drifts - Winds - Hadley, Ferrel and Polar Rotations/Cells
  6. 6. Figure 13.2 p351 This map shows the earth’s major climate zones along with major warm and cold ocean currents that distribute some of the earth’s moisture and heat.
  7. 7. Figure 13.3 p352 Three climate zones—tropical, temperate, and polar—are created by uneven solar heating of the planet, the rotation of the earth on its axis, and the resulting prevailing winds and ocean currents that distribute heat and moisture unevenly around the globe.
  8. 8. Atmospheric Warming and Cooling Life depends on natural Greenhouse Effect - Heat trapped keeps earth warmer - Greenhouse gases - Water - Carbon dioxide - Methane - Nitrous oxide - Climate has changed in past (warmer and cooler) - Current rate of change may be unprecedented
  9. 9. Environment, Fourth Edition by Peter H. Raven and Linda Berg. The Greenhouse Effect
  10. 10. Figure 13.5 p353 These maps show the changes in ice coverage in the Northern Hemi-sphere during the past 18,000 years.
  11. 11. Figure 13.8 p355 Scientists study ice cores, such as this one (a) obtained by drilling a deep hole in an Antarctic glacier. Thousands of such cores from around the world are stored at (b) the U.S. National Ice Core Center in Denver, Colorado.
  12. 12. Figure 13.4 p353 This graph shows the estimated global average temperatures of the atmosphere near the earth’s surface over 900,000 years. Vostoc Ice Core Data
  13. 13. Past Temperatures and Key Greenhouse Gas Concentrations
  14. 14. Figure 13.9 p355 This graph shows the global average temperature of the atmosphere at the earth’s surface between 1980 and 2011.
  15. 15. Carbon Dioxide and Climate CO2 plays important climate role - Increase in CO2, increases temperature - Long-term impacts - Effect recognized 100 years ago - Svante Arrhenius, Swedish chemist (1894) - postulated mankind was adding CO2 to atmosphere faster than Carbon Cycle can “handle” - Vostok Ice Core data is the key to the historic record
  16. 16. Carbon Cycle (black numbers are reservoirs and purple numbers are fluxes) Visionlearning.com
  17. 17. Figure 13.7 p353 These graphs compare changes in the estimated average atmospheric temperatures and CO2 levels during the last 400,000 years
  18. 18. How Scientists Study Climate Several ways to estimate previous climate - Tree rings - Ancient fossils - Marine sediments - Air bubbles in ice cores - Climate measured daily since 1982 - Build/run Models to predict climate trends - Compare model runs to Vostok/other data
  19. 19. What Are the Problems? Rapid Atmospheric Warming Mounting scientific evidence of rapid warming - IPCC (Inter-governmental Panel on Climate Change) - Four reports 1990, 1995, 2001, 2007 - Three basic conclusions - Since 1980 lower atmosphere has warmed - Computer models indicate due to human activities - Climate currently changing, will continue
  20. 20. Figure 13.10 p356 This graph represents the measurements of CO2 levels in the atmosphere at Hawaii’s Mauna Loa Observatory, 1958 – 2011. (The Mauna Loa Record)
  21. 21. Figure 13.11 p356 This diagram is a simplified summary of some of the factors built into models of the earth’s climate system. Red arrows show processes that warm the atmosphere and blue arrows show those that cool the atmosphere.
  22. 22. Figure 13.12 p357 These graphs show climate model projections of global average atmospheric temperature changes relative to the actual measured temperature changes between 1901 and 1997. The models were used to make projections using (a) only natural factors and (b) the combination of natural and human factors.
  23. 23. Human Activities and Climate Change CO2 major man-caused greenhouse gas - 1850, 285 ppm CO2 - 2011, 393 ppm CO2 - Likely to rise much more - Potential for a "tipping point“ (450 ppm?) Soot (black carbon) also contributes - Absorbs sunlight - Settles out quickly - Constant input has impact Most think that Fossil fuels and deforestation responsible for the increase in global temperatures since 1980.
  24. 24. Figure 13.14 p360 By (a) burning coal in power and industrial plants and (b) burning gasoline and diesel fuel in motor vehicles, we emit large quantities of CO2 into the atmosphere.
  25. 25. Figure 13.15 p361 In Brazil’s Amazon basin, large areas of tropical forest are burned every year to clear land for plantation crops and livestock grazing. These fires emit huge quantities of CO2 into the atmosphere.
  26. 26. Melting Ice Warming has major effect in polar regions - Increase 5-7 deg. F - Twice as fast as world average - Oceans transfer heat toward poles - Sea ice melting - Greenland ice sheet melting - Increase in sea level by 23 feet if it all melted - 1850, Glacier National Park had 150 named glaciers, now it has 25.
  27. 27. Figure 13.20 p364 Much of the Muir Glacier in Alaska’s Glacier Bay National Park and Preserve melted between 1948 and 2004, and it continues to melt today.
  28. 28. Figure 13.18 p363 Partial melting at the edges of the land-based ice sheet in Greenland increased dramatically between 1982 and 2007.
  29. 29. Melting Permafrost Permafrost (frozen soils) has large amounts of methane (CH4) trapped - Melting can release it - Been frozen for thousands of years - Much more potent greenhouse gas than CO2 - Although is shorter lived in atmosphere
  30. 30. Figure 13.21 p364 Ice forms in underground layers of frozen soil called permafrost (a), in polar regions such as this area of Arctic tundra (b). These areas have held stores (Peat) of methane and carbon dioxide for thousands of years.
  31. 31. Rising Sea Levels Glaciers melting, sea levels must rise - Thermal Expansion; warming water expands, occupies larger volume - Sea level may rise 3-6.5 feet this century - Keep rising for additional time - Coastal ecosystems flood - Many people live in threatened areas
  32. 32. Figure 13.22 p365 Projected climate change could submerge Male, the capital city of the Maldives, along with the 1,200 other small islands that make up this nation in the Indian Ocean.
  33. 33. Figure 13.23 p366 Areas of Florida, shown here in red, will likely be flooded if the average sea level rises by 3 feet.
  34. 34. Ocean Warming and Acidification Atmosphere temp increase raises ocean temperature - Bleaching of coral - Changes in habitats CO2 dissolves in water forms carbonic acid - Much CO2 emissions dissolve in ocean water - Ocean acidification - corals/mollusks can’t form shell Healthy coral reefs serve as habitats and food sources for an amazing variety of marine species. Figure 13.24 p366
  35. 35. Extreme Weather Events and Worsening Drought Climate change may cause extreme weather events - Intense and longer heat waves - Damaging storms - Extreme cold and blizzard conditions - More flooding Some areas drier - Warmer atmosphere can hold more water - 45% earth may experience droughts - More forest fires
  36. 36. Changes to Food Production Some Areas Could Improve - Canada, Russia, Ukraine - Agriculture may decline around the world - More serious pests - Higher food prices - Increase in food production in cooler areas - Decline in tropical/temperate areas - Possible international conflicts over resources
  37. 37. Threats to Human Health Potential effects on human health - Few deaths due to extreme cold - Intense heat waves - Higher CO2 favors insects, disease vectors - Diseases more frequent - Tropical diseases may spread - Hunger/malnutrition - Photochemical smog
  38. 38. Declining Biodiversity Major environmental problems - Loss/shift of habitats - More extinctions - Shifts in plant and animal ranges - many tropical species or moving towards poles and greatly expanding range - Increased diseases - Impacts of fires - IPCC, 1 out of three species will go extinct if global temps increase by 2.7-4.5 deg. F
  39. 39. Figure 13.25 p368 Because of warmer winters, populations of mountain pine beetles have exploded and munched their way through large areas of (a) whitebark pine forests (orange-colored trees that are dead or dying) in Yellowstone National Park in the United States, and (b) lodgepole pine forests in the Canadian province of British Columbia. .
  40. 40. The Range of Projected Effects Several climate-model projections - Some degree of change now unavoidable - How much caused by humans is debated - Urgent problem currently - Range of effects depends may depend on changes mankind makes now and in future
  41. 41. Figure 13.26 p369 These are some of the projected impacts of climate change based on average global CO2 levels and atmospheric temperatures.
  42. 42. What Can Be Done Two General Strategies Best to reduce greenhouse gas emissions quickly - Current practices are leading to climate change - Reduction by at least 40% - Reductions would decrease severity later - Change would continue for some time - Reduction of energy waste is key - Shift to low carbon sources of energy Mitigate effects of climate change - Move plant species to more suitable areas - Redistribute Agriculture
  43. 43. What Can Be Done Two General Strategies Mitigate effects of climate change (continued) - Earth’s climate may also be engineered - Carbon sequestration strategies - Millions of trees/wetlands - Caves/caverns filled with Carbon - Ocean fertilization/iron-ization - Phytoplankton explosion - Global dimming strategies - Mirrors - Sulfate particles in upper atmosphere
  44. 44. Figure 13.28 p373 Various geoengineering schemes have been proposed in hopes of warding off climate change or offsetting its harmful impacts.
  45. 45. Enacting an International Agreement and Sharing Technology Countries working together to slow climate change - 2007 Kyoto Protocol - 191/194 countries signed - Requires emissions to be sharply cut - No requirement for China (#1) and India - Negotiations failed in 2011 - U.S. failed to participate Taxing CO2 emissions Market-based approaches Key is slowing population growth
  46. 46. Figure 13-29 p376
  47. 47. Figure 13.30 p376 Weighing the pros and cons of cap-and-trade.
  48. 48. Some Encouraging Progress Dealing with climate change has been difficult - Do not want to change way of life - Waiting for technological fix - Skepticism - Changes appear to be coming - U.S. cities and states planning for climate change
  49. 49. Figure 13.31 p377 The Environmental Living and Learning Center at Northland College in Ashland, Wisconsin, makes use of renewable energy sources.
  50. 50. Harmful and long-lasting effects - Time to act is now - Need to reduce emissions by 40% to start - 80% would be better - Climate assumptions may not be correct - What happens if it is worse? A Look to The Future: A Narrow and Closing Window of Opportunity
  51. 51. What Would You Do? At home • insulate home, seal air leaks • energy efficient windows • energy efficient appliances, bulbs • efficient hot water heating Transportation • walking, biking, and taking public transportation • carpools • energy-efficient vehicles Purchases • eat less meat or no meat • buy reusable or recyclable products • minimize packaging • patronize companies that minimize effects

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