Tuesday, October 25, 2011

Berkeley temperature study does not prove global warming

See No change makes big news by Matt Ridley. Here it is:

"A comment on the piece by James Astill about the Berkeley temperature study. Most of the article is a sensible discussion of a deadly dull piece of statistics that changes nothing. But it's topped and tailed with claims that this leaves little room for doubters, and that the warming is "fast". Both these conclusions are badly wrong.

1. To think this will dampen doubt badly misreads what the doubt is about. What sceptics mainly doubt is not that there has been warming but the cause and the future projections. Here's what Richard Muller of the Berkeley study actually says in the Wall Street Journal:

"How much of the warming is due to humans and what will be the likely effects? We made no independent assessment of that."

So no change there.

2. Given that Muller used the SAME temperature station records as the other sets, his graph is no surprise at all. About the only thing Muller has added is a statistical attempt to find out if the urban heat island has exaggerated the effect. He says no, but his efforts in that regard have already been taken apart [update, I meant dissected, not demolished] by McIntyre, Watts, Eschenbach and Keenan (the latter in email correspondence with Astill). In any case, it turns out if you look at the data in Muller's article, rather than the press release, he very much does NOT get the same result. He gets a decline in the last decade then hides it by smoothing. [Update: Eschenbach has partly withdrawn this charge.] See Eschenbach's piece here: http://wattsupwiththat.com/2011/10/22/a-preliminary-assessment-of-bests-decline/#more-49792

3. Even if Muller is right, the last word of the Astill article is "fast". Yet Muller has merely confirmed that — in his analysis — the temperature is rising about as fast as the three surface temperature sets. Which is at a rate SLOWER than the zero emission prediction made by James Hansen in the 1980s — and ten times slower than the warming rate at the end of the ice age, by the way. Hansen told us to expect 2-4 degrees in 25 years if we continued emitting co2. Thatcher at the Royal Society spoke of a degree per decade. Muller confirms that we are experiencing about 0.16 degrees per decade and that's not including the sea, so the real number is lower. That's nearly an order of magnitude slower!!! How can that conceivably be called fast? We are exactly on course for the zero-feedback version of greenhouse warming — ie, a doubling of CO2 leading to a harmless 1.2C of warming. See the chart at this site.

4. The Muller study has not yet been peer-reviewed. It appears to have been rushed into print full of errors to suit Muller's self-publicity machine. Nothing wrong with you writing about scientific ideas before peer review, but when I asked Oliver earlier this year to cover the interesting work of Nic Lewis who has proved that the IPCC had statistically altered a chart of probability density function of climate sensitivity in a way that fattened the tail (from green to blue in the chart below) — implying far higher probability of high warming than the only empirical study of sensitivity warranted — Oliver said he would not cover it till peers and the IPCC had reacted. Double standard there.The IPCC reacted eventually, and quietly, by admitting that Lewis was right and publishing an erratum. Yet still not a word for your readers. The consequence of that is that the IPCC now admits that the probability of any warming over 2.3 degrees is highly unlikely. Now that is a big story, unlike the Muller thing"



5. Why does this matter? Here are two reasons. About 190,000 people probably died last year needlessly because of policies for making motor fuel out of food. Near where I live hundreds of jobs are about to be lost in hard-pressed south-east Northumberland because of Huhne's carbon rationing driving RTZ's aluminium smelter abroad. When people at Notting Hill dinner parties talk of the need for sacrifice, that's what they mean, not paying more for home-grown runner beans. Both these are a direct result of carbon emissions reduction policies. If you want to endorse the imposition of such hardships, you'd better have some darned good evidence that the cure is less painful than the disease. The Muller study merely confirms that the patient has the symptoms so far of a mild cold.

The coverage of this story in the press has been abysmal — as if somebody had written a paper saying that the euro has been increasing in value, therefore the eurosceptics were wrong and the media had taken them at face value. The Economist used to take apocaholic vested interests with a pinch of salt"

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.