Climate Fact: A Coming Coral Calamity?
Coral reefs are some of the most colorful, diverse, and productive ecosystems on the planet. In addition to being some of the world’s most popular tourist destinations, coral reefs provide humans with many immediate and tangible benefits including medicines, materials for jewelry, and buffers against storm surges. Most importantly, however, coral reefs provide food for billions of people – in Asia alone, coral reefs are the primary source of protein for an estimated one billion people. All of these benefits are being threatened by two trends: increasing ocean temperatures and decreasing ocean pH (or increasing ocean acidity). Between 1955 and 1998, world ocean heat content rose by 0.037 degrees Celsius. While this number may seem small, the same amount of energy it would take to raise the world’s ocean heat content by just 0.1 degree Celsius would be enough to raise the average global atmospheric temperature to 100 degrees Celsius (the Earth’s current temperature is about 15 degrees Celsius). This rise in temperature has made waters too hot for many corals. Another problem for coral has been rising carbon dioxide (CO2) levels. Carbon dioxide in oceans reacts with carbonate to form carbonic acid, and more CO2 means that that there is less carbonate available for corals to build the calcium carbonate that makes up their bodies. In just the last fifty years, 30 percent of the World’s coral reefs have died and another 30 percent have been severely damaged.
Seasons: Winter, Spring, Summer, Fall
(Sources: United Nations Atlas of the Oceans: The Value of Coral Reefs. Accessed Online 8 October 2007: http://www.oceansatlas.com/ and Orr, JC et al. “Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms.” Nature (2005): 681-686 and Miles, Edward. Multiple Stresses, Thresholds, and Ocean Acidification. Cannon House Office Building, Washington, DC. 20 September 2007 and Probasco, Mat. “Researchers Warn About Coral Reef Deaths.” The Associated Press 24 October 2006, and United States. Environmental Protection Agency. Climate Change, Wildlife, and Wildlands: A Toolkit for Teachers and Interpreters. Washington: GPO, 2000.)
