Coral reefs may start dissolving when atmospheric CO₂ doubles

Calcification rates in stony corals are expected to decline significantly in the near future due to ocean acidification. In this study we provide a global estimate of the decline in calcification of coral reefs as a result of increase in sea surface temperature and partial pressure of CO₂. This estimate, unlike previously reported estimates, is based on an empirical rate law developed from field observations for gross community calcification as a function of aragonite degree of saturation (Ω_arag), sea surface temperature and live coral cover. Calcification rates were calculated for more than 9,000 reef locations using model values of Ω_arag and sea surface temperature at different levels of atmospheric CO₂. The maps we produced show that by the time atmospheric partial pressure of CO₂ will reach 560 ppm all coral reefs will cease to grow and start to dissolve.