14. Global Warming Potentials 6.5 21 56 12.0 ±3 CH 4 Methane 1 1 1 50-200 CO 2 Carbon Dioxide 9,800 11,700 9,100 264 CHF 3 Trifluoromethane (HFC-23) 170 310 280 120 N 2 O Nitrous Oxide 23,900 6,500 100 yrs 34,900 16,300 3,200 SF 6 Sulphur Hexafluoride 10,000 4,400 50,000 CF 4 Carbon Tetrafluoride 500 yrs 20 yrs Global Warming Potentials 1996 Lifetime (years) Chemical Formula Gas
15. Background Information Carbon Cycle Atmosphere Hydrosphere Lithosphere CO 2 Biosphere Producers Consumers Decomposers Carbonates in Solution Carbonate Rocks Fossil Fuels Photosynthesis Combustion and/or Respiration
16. Background Information - Carbon Cycle Ricklefs, Robert E., The Economy of Nature, 3rd Ed.. 1993, W.H. Freeman and Co., New York Pools (billion metric tons) Fluxes (billion metric tons/year)
17.
18. Combined Annual Land-Surface Air and Sea Surface Temperature Anomalies (1861 to 2000, cf 1961 -1990). Two standard error bars shown on the annual number . Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
19. Northern Hemisphere Temperature Reconstruction (1000 to 2000) Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
20. Greenhouse Gas Concentrations in the Atmosphere IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001.
21. Variations of temperature, CH 4 & atmospheric CO 2 Intergovernmental Panel on Climate Change. IPCC Third Assessment Report - Climate Change 2001: The Scientific Basis – Technical Summary. Geneva, 2001. CO 2 (2001) CH 4 (2001) (> 2X scale) Data derived from air trapped within ice cores from Antarctica
22. More recent - CO2 & Temperature Two standard error bars shown on the annual number . Intergovernmental Panel on Climate Change. IPCC Fourth Assessment Report - Climate Change 2007 2009: 387ppm
28. … but reality is not average… mean <5% > 5% 15 o C 25 o C 35 o C 11 o C 25 o C 39 o C Historic ‘ average’ increase of 3 o C Average (3) + variability of 4 o C 22 o C 12 o C 32 o C Average + variability ‘ average’ increase May 1 st Historic
29. What we’re seeing….. NASA data for Jan-Apr 2010, 0.75 o C above 1951-80 base period
30. Moscow, August 2010. Hottest summer for at least 130 years, probably for last 1000 years, sparking forest fires and underground peat fires What we’re seeing…..
Put up yellow sun radiation slide draw how radiation is reflected as it hits the earth step by step on the black board
Variations of the Earth’s Surface Temperature: 1000 to 2100 The projected temperature changes from 2000 to 2100 for the 6 illustrative SRES scenarios are shown in comparison to temperatures observed over the last millennium. The “several models all SRES envelope” shows the temperature rise for the simple model when tuned to a number of complex models with a range of climate sensitivities. All SRES envelopes refer to the full range of 35 SRES scenarios.
Projected Changes in Annual Temperatures for the 2050s Although regional patterns are not projected with high confidence, land areas are projected to warm more than the oceans, higher latitude regions (regions closer to the poles) are expected to warm more than equatorial regions, and the Northern hemisphere is projected to warm more than the Southern hemisphere.
Climate Change Impacts The changes in temperature, precipitation patterns, and sea-level rise that have been observed and that are projected to occur will have wide-ranging and some potentially devastating impacts on the natural environment and human societies. [potential impacts are described in detail in TAR.4.Impacts.ppt] Our health, agriculture, forests, water resources, coastal areas, and species and natural areas are all vulnerable to the projected climate changes. For a small degree of warming, there is a mix of benefits and harms; harms increase dramatically for the higher projected temperature increases. Scientists have made estimates of the potential direct impacts on the various sectors listed here, but in reality the full consequences are more complicated because impacts on one sector can also affect other sectors indirectly. [Suggested transition to slides in next file: As scientists began to document warming and debate began over whether warming could be attributed to human activities and if so, what to do about it, this led to the formation of the Intergovernmental Panel on Climate Change (IPCC), and an international policy framework (United Nations Framework Convention on Climate Change) for dealing with the issue.]