If the current trend of growth in carbon dioxide emissions continue, by 2100 the last coral reef dies. The only way to maintain the chemical environment that allows them to exist — is to reduce emissions as soon as possible and stronger. May also have to actively remove carbon dioxide from the atmosphere by mass planting or using special pumps.
Reefs seas are already suffering from acidification and warming water, and overfishing and coastal pollution. Carbon emissions are reduced by 0.1 pH water, causing the coral polyps can no longer with the same success to increase their limestone skeletons. On the other hand, the geological record shows that the ancient ocean acidification, though accompanied by mass death, did not result in the disappearance of coral.
|Coral of the genus Porites (photo Louis Wray / Creative Commons).|
The staff of the Carnegie Institute (USA) analyzed the results of computer simulations performed by 13 groups from different countries, dedicated to the interaction of the ocean to the atmosphere when the concentration of carbon dioxide in the air. This so-called active biogeochemistry previously commonly overlooked when modeling climate.
Coral polyps are in dire need of aragonite — a form of calcium carbonate. When the concentration of carbon dioxide in water is increased (the ocean absorbs carbon dioxide from the atmosphere), the availability of calcium carbonate decreases. The normal concentration ratio of aragonite in the water — 3? 3.5.
There is no exact rule that allows to link the figure to the health of the reefs. But judging by the paleoclimatic data, the pre-industrial era (ie before carbon pollution), this number is higher than 3.5.
Models that have been analyzed by scientists, were prepared for the big report of the Intergovernmental Panel on Climate Change, which comes out next year. The researchers compared the results of the simulation with the data for 6 thousand reefs, and it is two-thirds of the world total.
At the conference of the American Geophysical Union held in early December, coauthor Ken Caldeira showed the carbon emitted in the coming decades, could affect the fate of corals. If emissions will decline, trees — planted, pump — pump, then 77? 87% of reefs will remain safe, for aragonite saturation water will exceed the mark 3.
If nothing changes, all reefs will be surrounded by water containing less than 3 aragonite. You can not really say for sure that it will lead to their global extinction, but Mr. Caldeira warns of this experiment is better to abstain.
Prepared according to ScienceNOW.