There has been an interesting online debate involving James Hansen, and Joe Romm (from and the Center for American Progress). After Hansen released his essay Tell Barack Obama the Truth — The Whole Truth (also reproduced by Barry Brook at, Romm responded with a blog post An open letter to James Hansen on the real truth about stabilizing at 350 ppm. Hansen’s strategy is to aim for a target of 350 ppm or less with an approach based on a carbon tax where 100% of the dividend is returned to households; a halt to construction of new coal-fired power plants unless they store the CO2 that they produce; and an R&D program in technologies that some will find controversial. Romm’s approach is to aim for a target of around 450 ppm with an approach based on a “WW2-style effort”. Both of their essays are worth reading, as are the comments threads.

Since then, Hansen has given a speech to the American Geophysical Union that summarises his “Target CO2” paper (and is even scarier than his “Target CO2” paper). He has also written a letter to Michelle and Barack Obama, which has gotten some media attention in Australia because he stated that “Australia exports coal and sets atmospheric carbon dioxide goals so large as to guarantee destruction of much of the life on the planet”. This isn’t the first time Hansen has commented on Australia’s climate policy, he also said in October that Australia’s approach to climate change “if adopted globally, practically guarantees destruction of most life on the planet.”