Qualia

Climatologists, like Walter Broecker and James Hansen, have predicted a warmer climate due to the accumulation of greenhouse gasses in the atmosphere from the burning of fossil fuels. Geologists take a longer view. On a geological timescale, it appears that the Earth has long oscillated between “greenhouse” and “ice house” conditions. During greenhouse periods, the average global temperature has been a balmy 22°C (72°F), quite a bit warmer than the 2012 average of about 14.4°C, one of the hottest years that climatologists have actually recorded. But all of man’s time on Earth has so far been spent within a few degrees of ice house conditions.