For example, on the topic of climate change he says:
We’re not talking about the ethics of sumo wrestling here; we’re talking, quite possibly, about the fate of civilization. It’s not a place to play snarky, contrarian games.The fate of civilization? Really?
That's exactly the type of exaggerated rhetoric that makes my skeptical hackles rise.
Yes, global warming will likely disrupt the lives of millions of people around the world, and will likely cause local extinctions and permanent migrations. But saying that the "fate of civilization" is at stake makes about as much sense as neo-cons saying that terrorism is an "existential threat" to America.
It all makes perfect sense; the Right exaggerates the terrorism threat so we'll spend more money on the military (mission accomplished on that one!), and the left exaggerates the global warming threat so we'll spend more money on their favorite stuff.
Maybe Krugman doesn't even realize he is biased; in all the time I've read his blog he's certainly never even hinted that his political views might cause him to ignore opposing points of view, cherry-pick evidence or use rationalization to justify his beliefs.