Most Coral Reefs Are at Risk Unless Climate Change Is Drastically Limited, Study Shows

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http://www.sciencedaily.com/releases/2012/09/120916160926.htm

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Coral reefs face severe challenges even if global warming is restricted to the 2 degrees Celsius commonly perceived as safe for many natural and human-made systems. (Credit: © Mikhail Tischenko / Fotolia)

ScienceDaily (Sep. 16, 2012) — Coral reefs face severe challenges even if global warming is restricted to the 2 degrees Celsius commonly perceived as safe for many natural and human-made systems. Warmer sea surface temperatures are likely to trigger more frequent and more intense mass coral bleaching events. Only under a scenario with strong action on mitigating greenhouse-gas emissions and the assumption that corals can adapt at extremely rapid rates, could two thirds of them be safe, shows a study now published in Nature Climate Change. Otherwise all coral reefs are expected to be subject to severe degradation.

Coral reefs house almost a quarter of the species in the oceans and provide critical services -- including coastal protection, tourism and fishing -- to millions of people worldwide. Global warming and ocean acidification, both driven by human-caused CO2 emissions, pose a major threat to these ecosystems.

"Our findings show that under current assumptions regarding thermal sensitivity, coral reefs might no longer be prominent coastal ecosystems if global mean temperatures actually exceed 2 degrees Celsius above the pre-industrial level," says lead author Katja Frieler from the Potsdam Institute for Climate Impact Research. "Without a yet uncertain process of adaptation or acclimation, however, already about 70% of corals are projected to suffer from long-term degradation by 2030 even under an ambitious mitigation scenario." Thus, the threshold to protect at least half of the coral reefs worldwide is estimated to be below 1.5 degrees Celsius mean temperature increase.

[CRH]

1. If the Caribbean is any indication, ...

safe temperatures have already been exceeded. The die off is rampant.

[AverageJoe90]

2. Sad story, but a necessary warning.

I doubt corals will go totally extinct....but 70% possibly suffering damage by 2030 is far more than bad enough, IMO. Some may not survive at all, even, by the time 2100 rolls around........