For two decades, progressives have castigated those questioning global warming as "deniers."
But the Economist, once firmly in the alarmist camp, recently acknowledged that global temperatures have remained stagnant for 15 years even as greenhouse-gas emissions have soared.
This may be because existing models have overestimated the planet's sensitivity. Or because the heat generated is sinking to the ocean bottom. Or because of something else completely.
How should a scientifically inclined liberal react to this trend? By inhaling deeply and backing off on economy-busting mitigation measures till science offers clearer answers.