Ars Technica reports: Three days before the beginning of a critical international climate conference in Paris, one of the world’s most famous climate scientists, James Hansen, has written a withering criticism of President Obama’s approach.

The Paris meeting will be attended by the heads of state of more than 130 countries, including Obama. Heading in, the United States has adopted a policy of calling for each country to set limits on carbon dioxide emissions, and will push for the adoption of technology to capture and store carbon dioxide. That approach, Hansen wrote in a new letter posted on his web site, “is so gross, it is best described as unadulterated 100 percent pure bullshit.”

In his “communication” published on Friday, Hansen argued that world leaders are eager to avoid the embarrassment of the last major climate meeting in Copenhagen in 2009, which was largely ineffectual. This time, world leaders will reach a deal, Hansen says, and pat themselves on the back. This deal will likely include pledges to cut emissions by 2025. For example, the United States is expected to aim for cuts of 25 percent based on 2005 carbon levels. [Continue reading…]