Eine Kleine Nachtphysik

(or a little physics about climate change. Or at least a few clarifications about some of the points being raised.)

Duty Calls: xkcd

In the wake of Climategate, a wide variety of mistakes and misapprehensions are being circulated on the Internet (as if that weren’t happening before).

For example, in this article from the Telegraph:

Phil Jones, the 57-year-old director of the CRU, is the man who has suddenly found himself the number one target of climate change conspiracy theorists the world over after he sent the most damaging of all the emails exposed by the anonymous hacker.
In one message, dated November 1999, he wrote: “I’ve just completed Mike’s trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) and from 1961 to hide the decline.”
Gotcha! say the global warming sceptics who have argued for years that average temperatures on Earth are, in reality, either stable or going down. Professor Jones defended himself by claiming the word “trick” was used out of context and simply referred to a legitimate method of handling data.

Well, actually not. “Hide the decline” had nothing whatsoever to do with the flattening of GMST (global mean surface temperature) post-2000, since that was written in 1999. It had to do with what is technically called the “divergence problem”, which is that the tree-ring data used in paleoclimate studies (such as the “hockey stick”) don’t match real, measured, temperatures in recent decades. The reason Jones would want to hide that is that if tree rings don’t register the current hot spell, they might have missed past hot spells as well, and thus couldn’t be used as proof that the current warming was unprecedented.

There are a bunch of other misapprehensions floating around, on both sides of the question. Here’s a grab bag.

So what does this all mean, bottom line? Not an awful lot — but just take all those claims you hear, on both sides, with a grain of salt.

Leave a comment