ScienceDaily (Mar. 27, 2007) — A new study indicates that future changes in ocean acidification caused by atmospheric carbon dioxide emissions are largely independent of the amount of climate change caused by those emissions.

The ocean plays a major role in the uptake of carbon dioxide emitted from fossil-fuel burning, helping to moderate future climate change. However, the addition of the gas to the ocean alters marine chemistry by increasing acidity (decreasing pH), posing a threat to shelled organisms and the predators that feed off them.

Cao et al. seek to quantify the effect of climate change on ocean acidity and on the calcium-carbonate minerals that form shells and skeletons. Using an Earth system model, the researchers find that ocean pH declines by 0.31 units by the end of this century if atmospheric carbon dioxide concentrations continue on a trajectory that ultimately stabilizes at 1,000 parts per million.

This increase in acidity occurs regardless of how much of a global-warming-related temperature rise takes place as carbon dioxide builds up to that concentration.

Title: Effects of carbon dioxide and climate change on ocean acidification and carbonate mineral saturation

Authors: Long Cao and Atul. K. Jain: Department of Atmospheric Sciences, University of Illinois, Urbana, Illinois, U.S.A.; Ken Caldeira: Department of Global Ecology, Carnegie Institution, Stanford, California, U.S.A.

Source: Geophysical Research Letters (GRL) paper 10.1029/2006GL028605, 2007

Adapted from materials provided by American Geophysical Union, via EurekAlert!, a service of AAAS.

Link to article: http://www.sciencedaily.com/releases/2007/03/070322110240.htm