The scientific article is at:
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf

The news article is at the link. Here are a couple of quotes from the new article:
""If you leave us at 450ppm for long enough it will probably melt all the ice - that's a sea rise of 75 metres. What we have found is that the target we have all been aiming for is a disaster - a guaranteed disaster," Hansen told the Guardian.

At levels as high as 550ppm, the world would warm by 6C, the paper finds. Previous estimates had suggested warming would be just 3C at that point."

"Hansen said that he now regards as "implausible" the view of many climate scientists that the shrinking of the ice sheets would take thousands of years. "If we follow business as usual I can't see how west Antarctica could survive a century. We are talking about a sea-level rise of at least a couple of metres this century.""

Back to Chris comments: My own outlook is not quite a bleak, but Hansen is the famous climate scientist and I am not. I have some background to evaluate what I read though. The 75 m rise pretty much certainly cannot happen this century. A couple of meters seems possible. I have not believed that all of Greenland or all of West Antarctica can melt this century, although both could be doomed to melt...I just think it will take longer. The UN panel consensus was less than 1 m this century but this estimate did not include accelerated ice sheet melting.

Chris

• CO2 levels