The Pew Center on Global Climate Change report, "Coral Reefs & Global Climate Change: Potential Contributions of Climate Change to Stresses on Coral Reef Ecosystems," will be released Friday at the annual meeting of the American Association for the Advancement of Science. The report, written by Kleypas with Robert Buddemeier (Kansas Geological Survey) and Richard Aronson (Dauphin Island Sea Lab), analyzes the likely impacts of climate change over the next century on coral reef ecosystems around the world. Kleypas and other scientists will discuss the threats to coral reefs at an AAAS session on February 14.
Scientists are finding that human emissions of carbon dioxide and other greenhouse gases, a primary cause of climate change, endanger reefs in two important ways. First, higher water temperatures are promoting coral "bleaching"--episodes in which corals and other reef-building species are weakened or killed after losing vital algae that lives within their tissues. Although coral species can recover from bleaching to some degree, repeated bleaching events are likely to eliminate sensitive organisms and reduce biodiversity. Elevated water temperatures are also thought to be a factor in the recent increase in coral diseases in the Caribbean.
Second, as carbon dioxide builds up in the atmosphere, more of it is dissolved into the ocean, which increases ocean acidity. This lowers concentrations of the carbonate ion, a building block of calcium carbonate that corals and other organisms use to grow their skeletons and build up the reefs. Ca