Just over the weekend, my inbox was filled with a discussion attacking climate science with assertions that “none of the models predicted the current cooling period” and, therefore, the entire concept of Global Warming rests on very shaky grounds.
Sigh …
Those involved in that discussion have now received links to an excellent article by AP science reporter Seth Borenstein. That article, Impact: Statisticians reject global cooling, merits praise because it is an excellent of inventive investigative journalism on a very public issue.
In the face of claims of cooling appearing in multiple venues and gaining visibility (such as via the truthiness-laden pages of Superfreakonomics (see here and here and, well, tens of other sites/posts )), being a centerpiece of misrepresentations by George Will and others, Borenstein decided to put metereological data under the searing examination of statisticians unaware of the data stream that they were seeing.
Berenstein (okay, “the AP”) gave the data to four statisticians and asked
them to analyze the data. The result:
the experts found no true temperature declines over time.
Without knowing what the data referred to, one statistician called it “cherry-picking” to assert that there was any sort of statistically meaningful ‘cooling trend’.
“If you look at the data and sort of cherry-pick a micro-trend within a bigger trend, that technique is particularly suspect,” said John Grego, a professor of statistics at the University of South Carolina.
The statisticians’ basic point: the starting date is key. If you play games and have 1998 as “the” starting point, there is a minor cooling in the intervening years. (Actually, not a cooling but a slight retreating, writ large, from very high temperatures.)
choosing a starting date can alter perceptions. Using the skeptics’ satellite data beginning in 1998, there is a “mild downward trend,” But doing that is “deceptive.” The trend disappears if the analysis starts in 1997. And it trends upward if you begin in 1999
Borenstein almost certainly will receit hateful (vitriolic) notes from deniers, self-proclaimed skeptics, and other anti-science syndrome sufferers who are unhappy with the results of a scientifically-sound path toward testing a hypothesis. Their loudly proclaimed hypothesis of a cooling globe since 1998 has, yet again, been tested and found wanting of a substantive basis.
Seth Borenstein: highly recommend reading.
See also: Brenden Demelle, DeSmogBlog, Statisticians Confirm: No Global Cooling Despite Skeptic Spin; Joe Romm, Must Read AP Story; and Greenfyre’s Independent statisticians reject global cooling fable. (Note: if you’re not aware of any of these three, they are all sites worth being part of your regular reading habits.)










5 responses so far ↓
1 Independent statisticians reject ‘global cooling’ fable « Greenfyre’s // Oct 26, 2009 at 4:59 pm
[...] on October 26, 2009 at 5:48 pm | Reply Myth of Cooling Globe shattered by AP-sponsored ‘blind’ test [...]
2 Scary Monsters (And superfreakonomics) « Greenfyre’s // Oct 26, 2009 at 8:35 pm
[...] old science that you can find in How and Why Wonder Books for ages 10 and up. … That bad. A Siegel captures it very well with “the truthiness-laden pages of Superfreakonomics“; ie there [...]
3 Progressive Nation » Blog Archive » Independent Statisticians Reject Global Cooling Fable // Nov 3, 2009 at 2:43 am
[...] Myth of Cooling Globe shattered by AP-sponsored ‘blind’ test [...]
4 Will George Will’s next column highlight this? // Nov 16, 2009 at 5:45 am
[...] what Will (and too many other deniers) falsely state is an 11-year cooling period (due to 1998 being (perhaps) the hottest year on record for natural cycles coming on top of [...]
5 RAnthony80 // Nov 22, 2009 at 6:46 pm
LOL.. Well in the 1880s we were in a mini Ice age. Try to find a Global warming chart that doesn’t start in 1880s.
You are right..the start date does screw up your numbers.. go back another 500 years.
Hope about going back 500,000 or a million or …
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