Tuesday, October 27, 2009

Term of the Day: "Independent Statistician"

Memo to the science-deniers who authored the recent, highly-suspect book Superfreakonomics (as well as the goofs at the "Hot Air Tour"): maybe you should have paid attention in your high school stats class.

That's the message from a recent Associated Press article that reports the findings of four independent statisticians (e.g., not on the payroll of Big Oil or one of its shill groups) who looked at claims that the Earth has actually cooled in the last ten years. According to the report:

Have you heard that the world is now cooling instead of warming? You may have seen some news reports on the Internet or heard about it from a provocative new book.

Only one problem: It's not true, according to an analysis of the numbers done by several independent statisticians for The Associated Press.
No way! They must have been pre-disposed to see trends that favor global warming. After all, scientists are all part of the arrogant liberal establishment!!!

In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented. The experts found no true temperature declines over time.

"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.
So, without knowing that the data had to do with global warming, four independent experts concluded that there was no decreasing trend in the data that has given rise to entire books and Astroturf movements designed to attack the settled science of global warming. It's like finding out your marriage has been a sham the whole time.

What did the independent experts find?

The AP sent expert statisticians NOAA's year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.

Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.
That's what happens when you're not an industry hack: your ability to perform elementary math improves dramatically.

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