Science Academies Warn Of Threat From Ocean Acidification

Rising carbon dioxide emissions are causing the world’s oceans to become dangerously acidic, threatening the health of coral reefs and shellfish, according to a statement from the national science academies of 69 nations. Saying that the rate at which the ocean is turning acidic is faster than at any time since the extinction of the dinosaurs 65 million years ago, the academies called for cuts in greenhouse gas emissions of 50 percent below 1990 levels by 2050, followed by steeper cuts thereafter. The academies warned that if atmospheric concentrations of CO2 — now at 387 parts-per-million and rising rapidly — should hit 450 to 500 parts-per-million by mid-century, many of the world’s coral reefs and shellfish may have trouble building the shells necessary to their survival. As the oceans absorb more C02, increasing levels of carbonic acid are produced, impeding the process of shell formation. “These changes in ocean chemistry are irreversible for many thousands of years and the biological consequences could last much longer,” said the statement from the academies, which includes those from the U.S., U.K., and China. The group said that the threat of ocean acidification should be a major reason for ratifying an international treaty reducing greenhouse gas emissions at this December’s climate summit in Copenhagen.