Coral reefs face severe challenges even if global warming is
restricted to the 2 degrees Celsius commonly perceived as safe for many natural
and man-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.