The Tällberg Forum has launched an international campaign focused on limiting the concentration of carbon dioxide in the atmosphere to 350 ppm. This is a follow-up to the objective proposed by the NASA’s James Hansen and his colleagues that the 350 ppm target is required to avoid global climate change with potentially very large and irreversible effects on human society and the natural environment. (Earlier post.)
The Tällberg Forum is holding an international conference in Sweden from 26-29 June to discuss how to achieve this lower level through “The Perfect Agreement and its Perfect Implementation” as an idealized design of a global deal that will serve as a benchmark for the UN Framework Convention on Climate Change (UNFCCC). The Convention is aiming to reach an international climate change agreement in Copenhagen in December 2009.
The Intergovernmental Panel on Climate Change (IPCC), in its 4th Assessment report, has indicated that achieving a 2ºC target will mean stabilizing greenhouse gas (GHG) concentrations in the atmosphere at about 445 to 490 ppm CO2 equivalents. This includes a number of greenhouse gases (not only carbon dioxide), and corresponds to about 400 ppm CO2 alone. A stabilization at 400 ppm CO2 equivalents corresponds to about 350 ppm CO2.
To get to the 350 ppm CO2 target put forward by Dr Hansen, the total greenhouse gas concentration will need to fall to about 400 ppm CO2 equivalents. This is at the low end of a range of stabilization concentration possibilities, according to the European Environment Agency.
James Hansen and Kofi Annan, former UN general-secretary are among King Carl XVI Gustaf of Sweden’s guests at the Tällberg Forum.