Extrapolating From A Single Data Point: Climate and Sandy

I have a new article up at Forbes on how crazy it is to extrapolate conclusions about the speed and direction of climate change from a single data point.

Positing a trend from a single database without any supporting historical information has become a common media practice in discussing climate.  As I wrote several months ago, the media did the same thing with the hot summer, arguing frequently that this recent hot dry summer proved a trend for extreme temperatures, drought, and forest fires.  In fact, none of these are the case — this summer was not unprecedented on any of these dimensions and no upward trend is detectable in long-term drought or fire data.   Despite a pretty clear history of warming over the last century, it is even hard to establish any trend in high temperature extremes  (in large part because much of the warming has been in warmer night-time lows rather than in daytime highs).  See here for the data.

As I said in that earlier article, when the media posits a trend, demand a trendline, not just a single data point.

To this end, I try to bring so actual trend data to the trend discussion.