Presentation Transcript

1. Global Warming

   GEOG 1112- Lecture 9

2. Chapter 4: Insolation and Temperature

   McKnight’s Physical Geography: A Landscape Appreciation, Tenth Edition, Hess
3. Insolation and Temperature Variations in Heating by Latitude and Season Land and Water Contrasts Vertical Temperature Patterns Global Temperature Patterns Global Warming and the Greenhouse Effect
4. Greenhouse Warming Natural mechanism that retains outgoing heat, keeping the Earth temperature more moderate
5. Climate Change Long-term changes in ‘typical’ climate patterns: Surface temperature and ocean temperature shifts Changing precipitation patterns Expansion and contraction of ice sheets Sea-level variations Vegetation migrations in response to climate shifts
6. Causes of Climate Change
7. Global Warming and the Greenhouse Effect Climate of Earth is becoming warmer, known as global warming Human-enhanced greenhouse effect Carbon dioxide main culprit Also methane, nitrous oxide Intergovermental Panel on Climate Change Figure 4-33
8. Global Warming and the Greenhouse Effect Factors Influencing climatic Warming and Cooling Earth is getting warmer. Intergovernmental Panel on Climate Change: global warming is “unequivocal”, very likely caused by human activity Greenhouse Gases: Carbon dioxide (CO2) Methane (CH4) Chlorofluorocarbons (CFC’s) Tropospheric ozone (O3) Nitrous oxide (N2O)
9. Atmospheric CO2 measured at Mauna Loa, Hawaii. Source: NOAA Climate Monitoring and Diagnostic Laboratory
10. Fig. 4-5, p. 91
11. Anthropogenic Sources of Atmospheric Change
12. CO2,CH4 and estimated global temperature (Antarctic ΔT/2 in ice core era) 0 = 1880-1899 mean. Source: Hansen, Clim. Change, 68, 269, 2005.
13. Fossil fuel CO2 emissions based on data of Marland and Boden (DOE, Oak Ridge) and British Petroleum. Source: Hansen and Sato, PNAS, 98, 14778, 2001.
14. Radiative Forcing
15. Global Warming and the Greenhouse Effect Greenhouse Gases: Carbon dioxide (CO2) Fossil fuel burning, forest destruction Methane (CH4) Rice cultivation, farm animal wastes, bacterial decay in sewage and landfills, fossil fuel use, biomass burning, wetlands (natural) Chlorofluorocarbons (CFC’s) Synthetic compounds Tropospheric ozone (O3) Motor vehicles Nitrous oxide (N2O) Motor vehicles, nitrogen fertilizer Some pollutants have a cooling effect Some factors are natural
16. Global Warming and the Greenhouse Effect The Temperature Record Net warming effect of 1.6 W/m2 Direct records show increase Variability Influence of volcanic activity
17. Global Warming and the Greenhouse Effect The Temperature Record Reconstructing temperature records: Thermometers Historical data Tree rings Coral growth Ice cores
18. Global Warming and the Greenhouse Effect Relationship between carbon dioxide and temperature Figure 4-35
19. Global Warming and the Greenhouse Effect Future Scenarios 2005 warmest year recorded since mid-19th century 2005, 1998, 2002, 2003,2006 five warmest years since 1400 Earth’s temperature up: 0.6º C (1.1º F) in last 30 years 0.8º C (1.4º F) in last 100 years IPCC projects increase in global temperatures between 1.8º C (3.2º F) and 4.0º C (7.2º F) by 2100
20. Surface Temperatures
21. Recent Temperature Anomalies
22. Sea Level Change
23. Sea Level Rise
24. Evidence of Recent Climate Change Glacial Retreat The Mt. Kilimanjaro glacier, which has survived the past 11,000 years, is currently at risk of disappearing by 2020 if present rates of melting continue;
25. Evidence of Recent Climate Change Enormous tracts of Siberian peatlands, with vast stores of carbon, are beginning to thaw and release carbon dioxide and methane into the atmosphere;
26. Evidence of Recent Climate Change The Larsen B ice shelf in Antarctica has lost volume as large chunks (some as large as the state of Rhode Island) have recently broken free and melted; The annual surface area of Arctic sea ice has declined eight percent over the past several decades;
27. Global Warming and the Greenhouse Effect Future ScenariosPotential future effects of greenhouse warming: Rise in sea level 28 to 43 cm (11.0 to 16.9 in) by 2100 Up to 92 million people displaced Spread of insect-borne diseases Climate boundaries shift Some regions wetter, some drier Agricultural patterns shift Human populations displaced Natural ecosystems displaced Arctic thawing More variable, extreme climate
28. Discussion Questions Is the world warming? Will it continue to warm? What will warming cost us in property damage and lives? What are the costs of ameliorating the warming trend? What are the potential advantages of changing the way we do business?
29. The Problem with Global Warming
30. Is it Time to Act? Nine of the top 10 warmest years globally have occurred since 1995 Across the Northern Hemisphere, the 1990s were likely the warmest decade of the past millennium-and possibly the past 2,000 years
31. Missing Carbon Sink
32. Variation in Predictive Models Most scientists agree that it is happening But disagree on the extent and the outcomes
33. Intergovernmental Panel on Climate Change Climate Change 2007: The Physical Basis
34. Global Warming Impacts Health Water Forests Agriculture Deserts Coastal Areas Fisheries
35. Global Warming and the Greenhouse Effect International efforts to reduce greenhouse emissions: 1992 Rio de Janeiro Earth Summit 1997 Kyoto Protocol 1998 Buenos Aires 2005 Montreal Solutions will require use of energy sources that produce power without releasing CO2: Solar Wind Geothermal Nuclear
36. Future Environments
37. How likely do you think it’s true that humans are changing the climate? Not at all- it’s all fear mongering A little bit, but not much we can do True, but nothing to worry about True, and we should start making changes True, and we need to change right now!
38. Enter question text... Enter answer text...
39. How many degrees C should we allow the Earth to warm before changing our way of living? 1 2 3 4 5 6 7 8 9