What does increase in Arctic ice mean for the EPA?

After the revelation came yesterday that Arctic ice has actually increased despite predictions it would disappear, the Washington Examiner's Michael Barone wonders:

In previous reports the IPCC has misinterpreted data a plenty. In one case it took a journalist's prediction that the Himalayan ice sheet would melt in 2350 and changed that date to the considerably less remote 2035. So it's not likely that the IPCC is going to proclaim that we face global cooling rather than global warming.

Even so, I am reminded by a characteristically bracing blogpost by my former American Enterprise Institute colleague Michael Greve that the supposed consensus that global warming is a threat was the basis of the Supreme Court's 2007 ruling in Massachusetts v. EPA requiring EPA to regulate carbon dioxide emissions. The Court ruled that carbon dioxide, which is non-poisonous and necessary for animal and plant life, is a pollutant subject to regulation under the Clean Air Act of 1970. But if carbon dioxide is not producing supposedly dangerous global warming, there is no basis for calling it a pollutant. Is it possible that Massachusetts v. EPA will some day be reversed?