The liberal blogosphere has done a good job of trouncing George Will's terrible column on climate change into the mud. The minor thing I'll add is the probable source of Will's incorrect statement that "global sea ice levels now equal those of 1979." It's this Daily Tech article from January 1 that was picked up widely among denialists and torn to pieces by Tamino.
The Daily Tech article was essentially wrong and deliberately misleading, but did use one true factoid. Due to the high level of annual variability in sea ice, there was one point last December where the ice was about the same as in December 1979. The problem with cherry-picking though as opposed to honest trendlines is that it's easy to screw up, and "now" is no longer December, and sea ice is once again in line with the trend of overall decline. I expect the reason that Will isn't responding to inquiries is that "I'm too incompetent to cherry-pick correctly" doesn't sound satisfactory.
I read once that the checkout tabloids usually start with a kernel of truth for their stories. A report of someone seeing a amputated leg twitch becomes "severed leg stands up, runs fifty feet." If Will is going to use this level of honesty, there are better publications to take his stuff than the Washington Post.