Krugman discovers peak oil

Peak oil: Paul Krugman seems to believe it.

Conventional oil production has been flat for four years; in that sense, at least, peak oil has arrived. 

He even starts to grok the tar sands angle:

True, alternative sources, like oil from Canada’s tar sands, have continued to grow. But these alternative sources come at relatively high cost, both monetary and environmental.

Perhaps this will mean greater discussion of peak oil, at least among liberals/progressives, given Krugman's stature.