We would like to draw your attention to session BG3.1 "Ocean acidification and its impact on polar ecosystems" that we will convene at the next EGU meeting (Vienna, 3-8 April 2011).

Ocean acidity has increased by 30% since preindustrial times due to the uptake of anthropogenic CO2. It is projected to rise by another 100% by 2100 if CO2 emissions continue at current rates. Polar seas are considered to be particularly vulnerable to ocean acidification because the high solubility of CO2 in cold waters results in naturally low carbonate saturation states. CO2-induced acidification will make these waters undersaturated with respect to calcium carbonate and, therefore, corrosive for calcareous organisms. By the time atmospheric CO2 exceeds 490 parts per million (2040 to 2050, depending on the scenario considered), more than half of the Arctic Ocean is projected to be corrosive to aragonite.

Presentations from the EPOCA Svalbard experiments (2009 and 2010) are particularly welcome as are all contributions addressing ocean acidification in polar areas, including observations, experiments and modeling.

Abstracts can be submitted from 1 November 2010 until 11 January 2011 on the meeting web site.

We look forward to seeing you at this session!
Jean-Pierre Gattuso, Ulf Riebesell and Stephen Widdicombe