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Tuesday, November 25, 2008

Global Cooling

Geophysicist Phil Chapman argues that the Earth is actually cooling.

Jens Bischof, author of "Ice Drift, Ocean Circulation And Climate", thinks we're due for a cold snap as well.

What the heck? Should we get sunscreen or parkas?

4 comments:

mijopo said...

There has been fairly extensive discussion of the sunspot theory and the cooling trends of '07. For one, I think we've seen a fairly fast bounce back of temperatures since then, suggesting it was El Nino related and I think the Sun Spot thing has been largely debunked, e.g., http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm.

The presence of a small handful of crackpots willing to argue against general consensus doesn't make the fact of the matter a coin flip. (This guy, Chapman, "published" in The Australian, that's a newspaper, isn't it?)

mijopo said...

I agree on the importance of scepticism and don't rest on consensus, but I do find the arguments, insofar as I understand them, convincing.

You bring up political motivation and that's a good point and it's part of why I have a hard time taking opposition to GW theory seriously, it seems an obviously politically motivated grasping at straws. And please look into the funding that Lindzen has received from oil companies if you're worried about political interests.

But I may be wrong, I claim no expertise here. I'm just saying the evidence seems compelling to me, almost all scientists seem to agree, (I note that you're also willing to factor this in as justification when you say "some of our best scientists), and if we're forced to make hard decisions the way to proceed seems adequately clear.

Erik said...

Okay, fair enough, in so far as I really don’t know if Chapman is a crackpot. The second fellow I cited is a Ph.D. researcher who (as I mentioned) has written an entire book on some arcane aspects of the analysis of polar ice (I don’t think I’ll be reading it any time soon, sorry to say, but I’m sure it’s very engaging). So, perhaps the crackpot claim is legit.

But I must say that other dissenters seem more troubling, like distinguished Alfred P. Sloan Professor of Atmospheric Science at MIT, Richard S. Lindzen. What’s his bag? Crackpot too? (I thought MIT did some decent vetting of their faculty.)

Anyway, it may be of interest to GW proponents that Lindzen specifically questions the claim of “consensus”. See his op-ed in the Wall Street Journal: http://www.opinionjournal.com/extra/?id=110008597.

Now, whatever one thinks of Lindzen’s claim that the GW consensus is illusory (and I think we should give him a fair hearing, regardless of our propensities toward or against GW), as a philosopher (and computer scientist, though I guess that doesn’t much count), I’d like to urge some caution at taking scientific consensus too seriously. We can, for the sake of this point, just assume that there is a consensus on GW (even if there’s not, according to Lindzen). What follows? The history of science teaches us that “consensus” on matters scientific is hardly a good gauge of truth.

We accept consensus opinion provisionally, as representing our best attempts to make sense of some set of observations. But, from Ptolemy to Copernicus, to Galileo and the entire edifice of Aristotelian physics (rooted both in the Catholic intellectual tradition spearheaded by, inter alia, Thomas Aquinas, and in the general learned consensus of the Western world prior to the 17th century), to no less than Charles Darwin himself, bucking prior theories of origins promulgated by Lois Aggasiz and now-discredited theories such as Lamarcks; prior consensus has in general been no bulwark against future, major theory changes.

Now, an objection here is that we must go with what we believe best at the time. Sure, but a healthy dose of humility, proportional to the scope of the theory--and especially of it purports to predict the future behavior of complex systems, like the weather--would be wise.

Okay, these comments about the history of science were intended as a warm-up, or background, to a discussion about the status of GW. Theories are debunked, sure. But here’s the more specific point: if the consensus seems suspiciously political, as I think the GW “consensus” is, I’d give much due to the vocal minority. Why? They have no apparent reason to dissent, other than in the interests of true science, and they have a very large incentive to go along with a movement that has become through and through political. (This latter point is why, I think, many people "smell a rat" with theories like Intelligent Design, because they connect the theory with a prior non-scientific or political aim. The minority view seems the more political, or extra-scientific. With GW, the converse seems the case.)

So, just to make my point as clear as I can, consensus is suspicious specifically when it seems political. No sane scientist doubts General Relativity (though it is at least theoretically possible that it may be proved wrong some day). But qualified scientists—indeed, some of our best scientists, such as Lindzen—have serious doubts about GW. This strikes me as noteworthy. It ought not to be glossed over or bullied and silenced. It could be, in fact, that these dissenting views are the soil out of which a future climate Darwin may emerge (showing that the Earth is actually cooling, or just that the warming models are demonstrably wrong in some or other respect), or a new Galileo, or Copernicus.

Or perhaps not. But at any rate, I’m inclined to be careful. I’ll support alternative energy plans without taking a hard damn-straight-it’s-true line on theories about the future behavior of large, complex systems that we still, in spite of our great strides, don’t fully understand. We can get the laudable results without overreaching on what counts as established. And we preserve that great bastion of the civilized world, a skeptical search for truth. Why not?

Erik said...

Apologies, I have been messing around with my post, and now it's posted ahead of your response. I'll see if I can fix it.

On your final comment, about being forced to make hard decisions, I suppose I'd suggest that we're not. We can aggressively support reducing our dependence on carbon fuels (esp. oil) for all sorts of reasons that preserve our skepticism about understanding complex systems. For instance, to have a healthier environment for ourselves and our children. To create jobs. To reduce our vulnerability to OPEC and in general to regimes in the Middle East that foment radical, anti-American views. This is the line I'm taking, and it doesn't require me to take a hard line on GW. We’re not “forced” to take a position on GW qua scientific theory at all. We can simply keep trying to understand climate change, while aggressively pursuing alternative energy solutions.