A significant reduction in greenhouse gas emissions is needed for coral reefs to continue to grow 80 years from now, a study suggests. Ocean warming and acidification pose increasing threats to coral reefs and the calcium carbonate frameworks of coral-rich biodiversity hotspots. Relatively little is known about the potential global impact of climate change on the net calcium carbonate production in coral reefs. Christopher Cornwall and colleagues analyzed data from 183 reefs worldwide to estimate the effects of ocean warming and acidification and modeled the size of the effects under three scenarios representing the range of future greenhouse gas emissions. Net carbonate production in every coral reef analyzed is expected to decrease under all three scenarios. The models predicted that 63% of reefs will continue to grow in 2100 under the scenario known as Representative Concentration Pathway (RCP) 2.6, but 94% of the reefs will be eroding by 2050 under RCP8.5. Under RCP4.5 or RCP8.5, declines in net carbonate production are projected to be so severe that reef growth will cease globally by 2100. The predicted declines are largely attributable to reduced coral cover due to bleaching events. According to the authors, rapid reduction of carbon dioxide emissions is needed to protect coral reef ecosystems and their critical ecological functions.
Article #2020-15265: "Global declines in coral reef calcium carbonate production under ocean acidification and warming," by Christopher Cornwall, Steeve Comeau, et al.
MEDIA CONTACT: Christopher Cornwall, Victoria University of Wellington, Wellington, NEW ZEALAND; tel: +642108360720; email: christopher.cornwall@vuw.ac.nz
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Proceedings of the National Academy of Sciences