Wednesday, February 27, 2008

Addendum to my interview with Dr. Cooksy

This post is meant to be read after the one below.

A few clarifications I should have made prior to posting.

In response to questions number one: "Are you saying that atmospheric scientists are saying that it exists without question or there have been no questions because it just doesn't exist? I can read it both ways..."

Dr. Cooksy:

I believe that the question was asked and was answered, to the extent that anything in climate science can be, years ago. The answer they find is, the global climate is changing with unprecedented rapidity, and the change can be largely attributed to human activity. Questions will always remain as to the precision of models that try to predict the future. Waiting for those questions to be resolved is futile, because science by its nature doesn't provide any answers with absolute certainty. But if there is any appearance of substantial controversy beyond that, it lies entirely outside this community of scientists.

Still question number one, me: "Their prediction being that global warming is or is not going to be a problem? I hope this doesn't sound naive but sometimes it is hard to differentiate where the information is coming from. Depending on the source, 'scientists' seem to be claiming the whole spectrum of various problems/non-problems. Especially in the last ~year or so, it has been REALLY difficult to nail down what the scientific community, as a whole, thinks about various things. Not everyone will concur, of course, but it's never seemed so impossible to find the mean of opinions/theories."

The only climate models I'm aware of are those that predict long-term global warming, acidification of the oceans, significant increases in severe weather, and so on. And as these effects were predicted years ago, and are already being observed today, early versions of those models have already passed a significant test of validity. If there were believable climate models that showed this just going away, we'd hear about them in a big way.

To emphasize something from the above, scientists aren't going to give you an absolute answer. Even if there was an absolute answer to give, scientific enterprise would move away from that to the areas where questions remain. So if you read any scientific papers on the subject, there will be a lot of emphasis on the uncertainties -- that's a constant of good science. It's important to maintain that questioning perspective, even if you're dealing with an issue of potentially enormous societal impact, because to abandon it threatens the quality of the science.

For that reason, I'm intentionally vague about the value judgments, like what constitutes a 'problem.' As scientists, it's not for climate researchers to tell us whether it's a bad thing that there won't be any Arctic sea ice a century from now. But they're not studying *if* it's going to disappear any more; they're just studying how long it might take.

If you want to know what scientists think about those value judgments, I'd recommend seeing what their organizations have to say. These bodies are expected to review the science, and synthesize what they can to obtain a big-picture viewpoint. In the US, the American Association for the Advancement of Science and the National Academy of Sciences serve this function. I don't think that they've been vague about this at all. AAAS in particular has been vocal about the scientific consensus for years. For a non-US perspective, the Royal Society in the UK is analogous to our NAS.

If you read about any science secondhand, it can be made to look controversial because it never answers any questions absolutely. On top of that, I think there are perfectly valid controversies about the ramifications of global climate change from the standpoints of politics and economics, to say nothing of scientific questions that involve greater or more complex extrapolation (such as far-future climate prediction, biological and ecological impacts). It's easy for the scientific and the non-scientific controversies to become confused in popular reporting.

Good stuff!

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