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A Conspiracy of Statisticians, No Doubt
Statisticians reject global cooling
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.
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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.
Saying there's a downward trend since 1998 is not scientifically legitimate, said David Peterson, a retired Duke University statistics professor and one of those analyzing the numbers.
Identifying a downward trend is a case of "people coming at the data with preconceived notions," said Peterson, author of the book "Why Did They Do That? An Introduction to Forensic Decision Analysis."
Let's just remind ourselves what those NOAA data look like.
8 comments:
But it's cold outside right now! That's proof isn't it? =:)
Can you point to skeptics who claim that there is an ongoing downward trend? I suppose there probably are some, but I'm not aware of them.
What I've generally heard is merely the claim that the observed temperatures have not shown an increase over the last 10 years or so. This is simply a matter of looking at the numbers--statisticians are not needed to evaluate that claim.
I think the main claim of global warming skeptics is that the warming/cooling trends are largely independent of human activity -- that, for example, the continuous upward trend we should in the last decade thanks to the increased industrialization of China (and to a lesser degree India) isn't there. The trough around 1910 and the dip in the early '50's seem to give at least a little credence to that; were those really eras in which carbon emissions somehow lagged?
Ed,
Last week there was this over at Millenial Star. Just from quick Googling, you might try some of the articles listed here also.
Nathan,
I think only the last 50 years or so of warming has been attributed to humans. CO2 is not the only factor, of course. From what I understand, the cooling around 1950 is attributed to aerosol pollution that has since been removed--or at least doesn't mask the warming anymore.
Makes me wonder how a baseline is established in a fluctuating system so they can establish that THIS time (and this time ONLY) it's attributable to humans.
I believe Al Gore was sick for a few years in the early 50's
Jared,
Interesting.
I guess I tend to be familiar with a more informed class of skeptic. Like this guy:
http://www.climate-skeptic.com/
(He may be wrong, but if so he's wrong in less obvious ways, not claiming that CO2 has no warming effect or that we are now in a cooling trend.)
If we lived during 1915 and had this data, we might be going through a global cooling craze. Al Gore's smovie might be called "The inconvenient Freeze."
What I really want to know is what the data looked like a few hundred years before 1880, but the data are not available. If we had that data we would really be able to tell if this warming trend is a natural phenomenon or not.
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