Climatology vrs Economics

The exchange between Hansen and Krugman regarding the relative merits of a carbon tax vrs cap and trade as a means of reducing CO2 emissions reminded me of one of the more annoying things about climate change alarmists. Which is many of the same people who will argue that laymen should defer to the expert opinion of climatologists are themselves completely unwilling to defer to the expert opinion of economists. People who happily expound silly and ignorant economic arguments have little grounds for objection when other people come up with silly and ignorant climatology arguments. I have never seen a convincing explanation for why climatologists should be granted more deference than economists.