Earth Equity News

To Avert Climate Disasters, Atmospheric C02 Must Be Scaled Back to 350 PPMs: New Study Spearheaded by James Hansen. Press release, Columbia University, November 3, 2008. "Humanity must find a path to reduced atmospheric carbon dioxide, to less than the amount in the air today, if climate disasters are to be averted, according to a study [Target Atmospheric CO2: Where Should Humanity Aim? -- PDF preview, 35 pp] to be published in Open Atmospheric Science Journal by a group of ten scientists from the United States, the United Kingdom and France. They argue that such a path is feasible, but requires a prompt moratorium on new coal use that does not capture CO2 and phase-out of existing coal emissions by 2030. [On page 13 of the report the authors call for carbon pricing to eliminate fossil fuel use.] 'There is a bright side to this conclusion' according to James Hansen, the lead author on the study, 'By following a path that leads to a lower CO2 amount we can alleviate a number of problems that had begun to seem inevitable, such as increased storm intensities, expanded desertification, loss of coral reefs, and loss of mountain glaciers that supply fresh water to hundreds of millions of people.' Atmospheric carbon dioxide is already 385 parts per million (ppm) and it is increasing by about 2 ppm each year as a result of the burning of fossil fuels (coal, oil, and gas), with a smaller contribution from burning of forests. The authors use evidence of how the Earth responded to past changes of CO2 and on-going climate changes to show that atmospheric CO2 has already entered the dangerous zone. The authors suggest that global policies should have an initial target for atmospheric CO2 of 350 ppm. They note that the optimum CO2 level for maintaining a planet similar to that on which civilization developed is likely to be less than 350 ppm, but a 350 ppm target already reveals that dramatic policy changes are needed urgently. By the time such fundamental changes are achieved, knowledge will exist to help fine-tune the target CO2."