The predicted global-scale collapse of coral reefs within the next few decades due to climate change overestimates the speed of the decline and fails to adequately account for their potential for adaptation, say Australian researchers. However Professor John Pandolfi, of the University of Queensland's School of Biological Sciences, and colleagues say evolutionary adaptation can only happen if human impacts on reefs are reduced and carbon emissions dramatically reduced.
In a review article published in today's Science, Pandolfi says latest research shows climate change remains the greatest threat to the world's reefs.
However, he adds recent research shows there is great variation worldwide in reef organisms' ability to evolve and adapt to changes in sea surface temperature, ocean acidification, sea level and mineral saturation state.
"In the past when there have been dramatic changes in temperature or CO2 levels ... these are situations when reefs have responded in a very negative way," the chief investigator with the ARC Centre of Excellence for Coral Reef Studies says.
Pandolfi says shallow water tropical reef organisms existed throughout the past 540 million years of the Phanerozoic through periods when temperatures were more than 7°C higher than today and CO2 was more than 20 times greater than pre-industrial levels.
"[But] the overall evidence from the fossil record indicates that rates of change are crucial for determining ecological outcomes.
"We can't find any time in the geological past when the rate of CO2 rise is equivalent to that of today," he says.
Read More: http://www.abc.net.au/science/articles/2011/07/22/3273983.htm
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