Read the Sunspots
The Canada National Post has an interesting article by Professor Timothy Patterson that ascribes climate change not to global warming, i.e. warming due to the build-up of greenhouse gases in the atmosphere, but to solar variability. I don't know that I immediately buy it. But it does show that the science is far from the picture of unanimity environmentalists would have us believe. On that subject, Patterson writes
In some fields the science is indeed "settled." For example, plate tectonics, once highly controversial, is now so well-established that we rarely see papers on the subject at all. But the science of global climate change is still in its infancy, with many thousands of papers published every year. In a 2003 poll conducted by German environmental researchers Dennis Bray and Hans von Storch, two-thirds of more than 530 climate scientists from 27 countries surveyed did not believe that "the current state of scientific knowledge is developed well enough to allow for a reasonable assessment of the effects of greenhouse gases." About half of those polled stated that the science of climate change was not sufficiently settled to pass the issue over to policymakers at all.The fact that within my lifetime, climate scientists were talking about a looming ice age is proof of that.
posted by Doc at 9:01 AM
2 Comments:
Personally, I think it's more relevant to examine peer reviewed studies - scientists can have their theories but they need to back it up with empirical evidence and research that survives the peer review process. A survey of all peer reviewed abstracts on the subject "global climate change" published between 1993 and 2003 show that not a single paper rejected the consensus position that global warming is man caused. 75% of the papers agreed with the consensus position while 25% made no comment either way (eg - focused on methods or paleoclimate analysis).
Personally, I like to examine each argument on a case by case basis.
Take for example the theory that solar variation is causing global warming. The National Post series does an article on Sami Solanki, a German researcher into solar activity. He compared solar activity & temperatures over the past 1150 years and found temperatures closely correlate to solar activity. When sunspot activity was low during the Maunder Minimum in the 1600's or the Dalton Minimum in the 1800's, the earth went through 'small ice ages'. The sun has been unusually hot in the last century - solar output rose dramatically in the early 20th century accompanied by a sharp rise in global temperatures.
However, Solanki also found the correlation between solar activity and global temperatures ended around 1975. At that point, temperatures started rising while solar activity stayed level. This led him to conclude "during these last 30 years the solar total irradiance, solar UV irradiance and cosmic ray flux has not shown any significant secular trend, so that at least this most recent warming episode must have another source."
As for the ice age predictions in the 70's, that was largely unsubstantiated media hype. There was no studies predicting an imminent ice age - just some speculation that if the current cooling trend continued, we'd reach an ice age in 20,000 years. Quite a different situation to the avalance of peer reviewed scientific literature linking CO2 to global warming today.
As I said, I'm not trying to argue the position. And I don't know that I buy it. And I know I don't have the grounding in the field to make intelligent arguments one way or another. But regarding the stats about peer-reviewed papers, a couple of points.
First of all, those statistics do not necessarily contradict the survey Patterson references. The papers show that those working in the field believe the global warming theory. The survey says that a significant portion of the scientific community does not believe the scientific results are strong enough to start making political policy. So the scientists believe the theory but don't feel the science is sufficiently solid. No contradiction.
Secondly the lack of opposing views in peer-reviewed journals is not really surprising, is it? The system is not really designed to handle contrarian views. Once the community has settled on a generally accepted theory, opposing views are pretty well shut out. Who gets the research grants and the grad students? The kooks with the strange ideas or the guys towing the standard line? Obviously the latter, which means not much research being done on alternate views, and perhaps more importantly not many young scientists being raised up to question the orthodoxy. (And that in turn also breeds broader acceptance of the orthodoxy.)
Those peers doing the peer review, what would be their typical reaction to a dissenting view? Not too good. In my own field, papers advocating steady-state cosmology are extremely few and far between. Granted there aren't all that many of them out there, but about the only guy who could get one through nowadays is Geoff Burbidge whose status in the community is so high that he's a highly respected kook.
So you can't draw too many conclusions about the lack of opposing views in peer reviewed literature. I have nothing against peer review. It is certainly crucial to advancing good science. But it is a process that also is geared toward orthodoxy. You have to consider those selection effects before drawing conclusions.
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