CO2 Emissions May Exceed EPA Ocean-Quality Standards by Mid-century

For the first time a team of international scientists have reported that atmospheric CO2 emissions would cause the ocean waters to violate the EPA water quality criteria unless immediate action is taken to reduce emissions.

Stanford, CA. A global team of scientists have completed their study on the effect that human-induced carbon dioxide (CO2) emissions will have on ocean chemistry. The results will be published in the September 25, 2007, issue of the Geophysical Research Letters (GRL). The team found that the human induced CO2 emissions will alter ocean chemistry to the point where it will violate U.S. Environmental Protection Agency Quality Criteria [1976] and that this will take place by, approximately, 2050 unless emissions are dramatically curtailed now. This report is the first time that there has been any recognition that atmospheric CO2 emissions would cause the ocean waters to violate the EPA water quality criteria. The international team was composed of 25 leading researchers who state that carbon-dioxide induced “changes in ocean chemistry within the ranges predicted for the next decades and centuries present significant risks to marine biota” and that “adverse impacts on food webs and key biogeochemical process” would result. The study’s lead author Ken Caldeira from the Carnegie Institution Department of Global Ecology said “About 1/3 of the CO2 from fossil-fuel burning is absorbed by the world’s oceans. When CO2 gas dissolves in the ocean it makes carbonic acid which can damage coral reefs and also hurt other calcifying organisms, such as phytoplankton and zooplankton, some of the most critical players at the bottom of the world’s food chain. In sufficient concentration, the acidity can corrode shellfish shells, disrupt coral formation, and interfere with oxygen supply. ” The team’s work indicates a future that will see the atmospheric concentrations of CO2 (760 parts per million, or ppm) double by the end of this century unless action is taken. By mid-century atmospheric carbon dioxide concentrations could reach 500 ppm. As a point of comparison pre-industrial concentrations were 280 ppm and today's concentration is about 380 ppm. Caldeira said “Atmospheric CO2 concentrations need to remain at less than 500 ppm for the ocean pH decrease to stay within the 0.2 limit set forth by the U.S. Environmental Protection Agency [1976]. If atmospheric CO2 goes above 500 ppm, the surface of the entire ocean will be out of compliance with EPA pH guidelines for the open ocean. We need to start thinking about carbon dioxide as an ocean pollutant. That is, when we release carbon dioxide to the atmosphere, we are dumping industrial waste in the ocean.”