"Your books and articles are excellent resources for stimulating lively and insightful class discussions, and also give our students exposure to international issues that directly impact their lives." -Keith Cooper, Dean of Research, Cook College, Rutgers University
Chapter 3. Rising Temperatures and Rising Seas: Rising Temperature and Its Effects
Scientists at the Goddard Institute for Space Studies of the National Aeronautics and Space Administration (NASA) gather data from a global network of some 800 climate-monitoring stations to measure changes in the earth’s average temperature. Their direct measurements go back to 1880. 6
Since 1970, the earth’s average temperature has risen by 0.6 degrees Celsius, or 1 degree Fahrenheit. Meteorologists note that the 23 warmest years on record have come since 1980. And the seven warmest years since recordkeeping began in 1880 have come in the last nine years. Four of these—2002, 2003, 2005, and 2006—were years in which major food-producing regions saw their crops wither in the face of record temperatures. 7
The amount of carbon dioxide (CO2) in the atmosphere has risen substantially since the start of the Industrial Revolution, growing from 277 parts per million (ppm) to 384 ppm in 2007. The annual rise in the atmospheric CO2 level, one of the world’s most predictable environmental trends, is the result of the annual discharge into the atmosphere of 7.5 billion tons of carbon from burning fossil fuels and 1.5 billion tons from deforestation. The current annual rise is nearly four times what it was in the 1950s, largely because of increased emissions from burning fossil fuels. As more CO2 accumulates in the atmosphere, temperatures go up. 8
Against this backdrop of record increases, the projections that the earth’s average temperature will rise 1.1–6.4 degrees Celsius (2.0–11.5 degrees Fahrenheit) during this century seem all too possible. These projections are the latest from the Intergovernmental Panel on Climate Change (IPCC), the body of more than 2,500 scientists from around the world that in 2007 released a consensus report affirming humanity’s role in climate change. 9
The IPCC-projected rise in temperature is a global average. In reality, the rise will be very uneven. It will be much greater over land than over oceans, in the high northern latitudes than over the equator, and in the continental interiors than in coastal regions. 10
Higher temperatures diminish crop yields, melt the snow/ice reservoirs in the mountains that feed the earth’s rivers, cause more-destructive storms, increase the area affected by drought, and cause more frequent and destructive wildfires.
In a paper presented at the American Meteorological Society’s annual meeting in San Diego, California, in January 2005, a team of scientists from the National Center for Atmospheric Research reported a dramatic increase in the land surface affected by drought over the last few decades. The area experiencing very dry conditions expanded from less than 15 percent of the earth’s total land area in the 1970s to roughly 30 percent by 2002. The scientists attributed part of the change to a rise in temperature and part to reduced precipitation, with high temperatures becoming progressively more important during the latter part of the period. Lead author Aiguo Dai reported that most of the drying was concentrated in Europe and Asia, Canada, western and southern Africa, and eastern Australia. 11
Researchers with the U.S. Department of Agriculture’s Forest Service, drawing on 85 years of fire and temperature records, reported in August 2004 that even a 1.6-degree-Celsius rise in summer temperature could double the area of wildfires in the 11 western states. 12
Ecosystems everywhere will be affected by higher temperatures, sometimes in ways we cannot easily predict. The 2007 IPCC report notes that a rise in temperature of 1 degree Celsius will put up to 30 percent of all species at risk of extinction. The Pew Center on Global Climate Change sponsored a meta-study analyzing some 40 scientific reports that link rising temperature with changes in ecosystems. Among the many changes reported are spring arriving nearly two weeks earlier in the United States, tree swallows nesting nine days earlier than they did 40 years ago, and a northward shift of red fox habitat that has it encroaching on the Arctic fox’s range. Inuits have been surprised by the appearance of robins, a bird they have never seen before. Indeed, there is no word in Inuit for “robin.” 13
The National Wildlife Federation (NWF) reports that if temperatures continue to rise, by 2040 one out of five of the Pacific Northwest’s rivers will be too hot for salmon, steelhead, and trout to survive. Paula Del Giudice, Director of NWF’s Northwest Natural Resource Center, notes that “global warming will add an enormous amount of pressure onto what’s left of the region’s prime cold-water fish habitat.” 14
Douglas Inkley, NWF Senior Science Advisor and senior author of a report to The Wildlife Society, notes, “We face the prospect that the world of wildlife that we now know—and many of the places we have invested decades of work in conserving as refuges and habitats for wildlife—will cease to exist as we know them, unless we change this forecast.” 15
6. J. Hansen, NASA’s Goddard Institute for Space Studies (GISS), “Global Temperature Anomalies in 0.1 C,” at data.giss.nasa.gov/ gistemp/tabledata/GLB.Ts.txt, updated June 2007; climate monitoring stations from Reto A. Ruedy, GISS, e-mail to Janet Larsen, Earth Policy Institute, 14 May 2003.
7. Temperature change calculated from Hansen, op. cit. note 6; crops from USDA, op. cit. note 3; USDA, Grain: World Markets and Trade ( Washington, DC: various months).
8. Carbon dioxide data from Pieter Tans, “Trends in Atmospheric Carbon Dioxide–Mauna Loa,” NOAA/ESRL, at www.cmdl.noaa.gov, viewed 16 October 2007, with historical estimate in data from Seth Dunn, “Carbon Emissions Dip,” in Worldwatch Institute, Vital Signs 1999 (New York: W. W. Norton & Company, 1999), pp. 60–61; fossil fuel emissions calculated from International Energy Agency, World Energy Outlook 2006 (Paris: 2006), p. 493; deforestation emissions from Vattenfall, Global Mapping of Greenhouse Gas Abatement Opportunities up to 2030: Forestry Sector Deep-Dive (Stockholm: June 2007), p. 27.
9. Intergovernmental Panel on Climate Change (IPCC), Summary for Policymakers, in Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge and New York: Cambridge University Press, 2007), p. 13; IPCC, “Intergovernmental Panel on Climate Change and Its Assessment Reports,” fact sheet, at www.ipcc.ch/press, viewed 27 July 2007.
10. IPCC, Summary for Policymakers, op. cit. note 9, p. 15.
11. National Center for Atmospheric Research and UCAR Office of Programs, “Drought’s Growing Reach: NCAR Study Points to Global Warming as Key Factor,” press release (Boulder, CO: 10 January 2005); Aiguo Dai, Kevin E. Trenberth, and Taotao Qian, “A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming,” Journal of Hydrometeorology, vol. 5 (December 2004), pp. 1117–30.
12. Donald McKenzie et al., “Climatic Change, Wildfire, and Conservation,” Conservation Biology, vol. 18, no. 4 (August 2004), pp. 890–902.
13. Camille Parmesan and Hector Galbraith, Observed Impacts of Global Climate Change in the U.S. (Arlington, VA: Pew Center on Global Climate Change, 2004); DeNeen L. Brown, “Signs of Thaw in a Desert of Snow,” Washington Post, 28 May 2002; IPCC, Summary for Policymakers, op. cit. note 9, p. 13.
14. Patty Glick, Fish Out of Water: A Guide to Global Warming and Pacific Northwest Rivers ( Seattle: National Wildlife Federation, March 2005); Elizabeth Gillespie, “Global Warming May Be Making Rivers Too Hot: Cold-Water Fish Will Struggle, Report Says,” Seattle Post-Intelligencer, 24 March 2005.
15. Douglas B. Inkley et al., Global Climate Change and Wildlife in North America ( Bethesda, MD: The Wildlife Society, December 2004); J. R. Pegg, “Global Warming Disrupting North American Wildlife,” Environment News Service, 16 December 2004.
Copyright © 2008 Earth Policy Institute