Chapter 18: Global Climate Change

1. Chapter 18: Global Climate Change

2. Climate • area's long-term atmospheric conditions • temperature • humidity • wind • precipitation • barometric pressure • solar radiation • global climate change sees all these factors but considering the whole planet

3. Global Warming • increase in Earth's average surface temperature only

4. Rate of Atmospheric Changes • climate varies naturally overtime • the rate has increased • fossil fuel combustion and deforestation

5. Factors that Influence Climate • Milankovitch cycles • affect intensity of solar radiation • cause long-term temperature changes like glaciation • axial wobble→ 19 to 23,000 year cycle • variation in tilt→ 41,000 year cycle • variation in orbit→ 100,000 year cycle

6. Factors that Influence Climate • ocean absorption • CO2 is soluble in ocean water • but as temperature increases solubility decreases • phytoplankton absorbs some in photosynthesis • but not enough to compensate the extra CO2 produced today • positive feedback effect

7. Factors that Influence Climate • ocean currents • El Niño • air pressure decreases in western Pacific weakens the equatorial winds warm water flows east towards America shuts down delivery of nutrients fish population plumbs ocean birds, reptiles and mammals are also affected causes billions of economical losses www.noaa.gov

8. Factors that Influence Climate • La Niña • opposite of El Niño • cold waters extend to the west •El Niño/La Niña occur in cycles but these have become irregular • Scientists are investigating if there is any relation between irregularity of phenomena and air/water temperature increases www.noaa.gov

9. Thermohaline Circulation www.aw-bc.com/Withgott

10. Thermohaline Circulation • interruption might trigger rapid climate change (hypothesis) • data suggest circulation is slowing down

11. Study of Climate Change • proxy indicators: indirect evidence • ice cores • tree rings • sediment beds • coral reef

12. Study of Climate Change • direct atmospheric sampling • studies present-day climate • measures conditions of the atmosphere • concentrations of CO2 • monitoring of temperature

13. Study of Climate Change • Climate Models • simulations • mathematical • sophisticated computer programs that combine • atmospheric circulation • ocean circulation • atmosphere-ocean interactions • feedback • old data is used to see if the model works before it is applied

14. Current Climate Change Impacts • international panel of scientists (IPCC) • Fourth Assessment Report of 2007 (fig. 18.12) • contains thousands of studies • includes some predictions • addresses impacts of current and future climate changes • discusses possible strategies

15. Temperature Increase • most of the increase occurred in the last few decades • 1995-2006 were among the warmest on record • the number of heat waves have increased • a temperature increase of 0.2ºC is expected per decade if there is no control of emissions • IPCC predicts that by 2100 temperature will rise 1.8-4ºC depending on the emission scenario

16. Temperature Increase • Arctic changes of up to 3ºC are causing: • ice melting earlier • forming later • ice area is decreasing • thinner ice • no food for Inuit people • no food for polar bears • permafrost is melting

17. www.aw-bc.com/Withgott • Projected Temperature Changes for the decade of 2090-2099 IPPC calculates an increase of 0.1ºC per decade during the 21st century If we don't control the emissions it might get to an increase of 4ºC Ocean temperature is also increasing causing more intense hurricanes

18. Changes in Precipitation www.aw-bc.com/Withgott It is predicted to increase at high latitudes and decrease at low and middle Will worsen water shortages near the tropics Away from the tropics heavy precipitation will become more frequent increasing chances of flooding Droughts will become more severe and frequent

20. Melting Ice and Snow • risks of sudden floods • ice dams burst • reduction of summertime water supply • Artic/Antarctic ice surface is decreasing • resulting in larger darker ocean surfaces which capture heat and melt the ice faster • more dark surfaces on Earth reduces the albedo effect (light reflection) • as a result Earth's surface increases in temperature • positive: new shipping lanes and possible sites for oil and gas exploration

21. Rising Sea Levels 1938 1957 1972 1988 Backwater National Wildlife Refuge in Maryland marsh loss can occur if the rise is so fast that plants can't adapt

22. Rising Sea Levels • increase in level worldwide (17cm=6.7 in) • caused by • melting of ice • increase in runoff • increase in temperature→causes expansion of the volume of water already there

23. Problems with Rising Sea Levels • beach erosion • Florida, Washington, California, Texas, etc.

24. coastal floods • Venice, Italy

25. intrusion of salt water into aquifers • Los Angeles

26. loss of wetlands (mangroves) Guayaquil, Ecuador 1985 & 2000

27. loss of coal reefs • possible evacuations and migration of people • Island nations of Tuvalu and Maldives • loss of coral reefs • Maldives • possible evacuations and migration of people • Island nations of Tuvalu and Maldives

28. Climate Change Effects on Organisms& Ecosystems • alterations of the environment affect living organisms • adaptations take generations to acquire

29. Changes Attributed to Climate Change • temperature-dependant • plants blooming timing • animals breeding timing • birds migration timing • insects hatching timing • plants and animals are migrating north or higher elevations • bleaching of corals

30. Societal Impacts • Agriculture Related • earlier crop planting • shift of seasons • droughts and floods become more severe • predictions say production may increase but only temporarily • tropical and subtropical regions will lower production due to drought • hunger will increase

31. Forestry • longer & drier fire season • El Niño 97-98 • invasive species are more common • zebra mussel has arrived to Texas (4/09) • found in lake Texoma • insect and diseases are more frequent • elm trees Asian long horned beetle zebra zebra mussel

32. www.aw-bc.com/Withgott • Health Issues • respiratory diseases • more frequent • expansion of tropical diseases • floods overcoming sewage treatment • cholera • drowning more probable • hunger/ malnourished Deaths attributed to hot weather

33. Economics • people's perception of greenhouse effects has shifted • insurance companies began noticing increase in weather related disasters • industry also changed its point of view • An Inconvenient Truth helped spark the interest • companies are asking for legislation to require significant reduction in greenhouse gas emittions

34. Responding to Climate Change • mitigation or adaptation? • mitigation: pursue actions that reduce greenhouse gas emittions • energy efficiency • switching to clean renewable energy • farm practices that protect soil and water quality • prevent deforestation • recovery of gasses from landfills

35. adaptation: lessen the impact of future climate changes • seawall in Galveston • restricting coastal development • adjusting farm practices to drought conditions • modification of water management due to water conditions (floods, drought and salt intrusion)

36. Electricity Generation: Source of Greenhouse Gasses • it is the largest source (40%) of greenhouse gasses in the U.S. • 69% of the electricity in the U.S. is generated by fossil fuels. 50% is from coal. • ways to lessen the amount of fossil fuels used • encouraging conservation • switching to cleaner and renewable sources

37. Conservation and Efficiency: Saves Money in the Long Run • new technologies • high-efficiency light bulbs for example • ethical choices • EPA's Energy Star Program • more efficient electric appliances • efficient heating and cooling systems • efficient office equipment • turn off lights when not in use • turn off equipment when not in use

38. Sources of Electricity: Cleaner is Better • altering the types of energy we use • coal→oil→natural gas • natural gas produces half the emissions that coal produces • carbon sequestration (or carbon capture) will reduce the CO2 emitted to the air • use of OTHER energy sources • nuclear power hydroelectric geothermal • wind power ocean tides photovoltaic

39. Transportation • second-largest source of greenhouse gasses • 1/3 of the average American city is devoted to car use • average American family makes 10 trips/day • in the U.S. $200 million is spend daily in construction and repairs

40. Typical Automobile is Inefficient www.aw-bc.com/Withgott

41. Automotive Technology • fuel-efficient vehicles • hybrids • fully electric • alternative fuels (hydrogen cells)

42. Public Transportation • it is a lifestyle choice • car use decreases if living near their workplace • cities are working on the use of mass transit • people are including bike or walk • it is not accessible to everyone • Arlington refuses to include the train and bus system • Allen refuses to include the DART train system

43. Strategies to Reduce Emissions • double fuel efficiency in vehicles • decrease the miles you drive daily • maximize efficiency in buildings • double efficiency in coal power plants • switch from coal to natural gas • capture and store carbon dioxide (sequestration) • increase nuclear power production (3x) • increase wind (50x) & solar (700x) energy production • halt tropical deforestation • adopt conservation tillage on croplands

44. Mandates, Incentives or Both? • commandment-and-control policy • mandates are often resisted by industry • incentives may be more effective • whatever desition it has to be • fair • economically palatable • effective • enforceable

45. International Treaties • 1992 U.N. Framework Convention on Climate Change- voluntary approach • by 2006 • U.S. has increased its emissions by 17.9% • Germany decreased its emissions by 17.2% • U.K. dropped its emissions by 14.3%

46. 1997 Kyoto Protocol • mandates reduction of emittions to those of 1990 • reduction must be accomplished by 2008-2012 • U.S. refused to ratify accusing China and India of polluting without having to follow the protocol • creating resentment with allies • emittions had increased 11% worldwide by 2004

47. Climate Change Policies from Cities and States • in responce to inaction from the G.W. Bush administration and Congress • "meet or beat" Kyoto Protocol guidelines • mayors of 600 cities • urging state and federal government to act • California passed the Global Warming Solutions Act in 2006- 25% reduction of greenhouse gasses by 2020 • cap-and-trade program in the NE

48. Carbon Offset: Key to Mitigating • voluntary payment • pays the entity that is willing to reduce emissions that one in not willing to do • becoming very popular • carbon-neutrality: no net carbon is emitted • now it may not be as efficient as thought • has to be transparent and enforceable

49. Carbon Footprint • individual everyday life choices • reduce the emissions you create • transportation • EPA Star Program THE END www.starbozz.worldpress.com