Arnold Kling  

Climate Change--a Range of Views

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Mental Health Institutions and... My Book at a Discount...

First, there is Larry Summers.


Those who still deny that human activity is warming the planet, or claim that “business as usual” can continue indefinitely without profoundly adverse consequences, are increasingly seen as the moral and intellectual equivalent of those who deny that tobacco has adverse consequences for human health.

...The limited impact of Kyoto is evinced by the fact that carbon permits are now selling in the range of a negligible one euro a tonne.

...carbon markets are invitations to engage in pork-barrel corporate subsidy politics on a massive scale.


He promises a future column, where I'm betting he'll embrace the Pigou Club.

But I think it's time to fight back against the tobacco analogy. It is not the scientific consensus that makes me believe that there is a link between smoking and cancer. It is the evidence for such a link that is compelling. It is the weakness of the evidence of the link between man-made carbon dioxide and climate change that makes the scientific consensus less persuasive than the tobacco-cancer link.

In the spirit of trying to examine the evidence, last evening I attended this event, sponsored by the World Affairs Council of DC.

Michael MacCracken was the spokesman for the scientific consensus. He is the sort who believes that only scientists like himself are qualified to discuss the issue. His attitude was one of someone forced to share a panel with a bunch of wingnuts. His contempt for other points of view extended to those who think that carbon taxes are the best policy option. Evidently, the scientific consensus is that command-and-control is better, although he did not use that term.

During the question period, I asked about climate engineering, and I pointed out that the Stern report was implicitly calling for a sacrifice of $500 billion per year. McCracken described climate engineering ideas, and he made them sound outlandish, so presumably very costly. But he never came back to the issue of comparing that cost to $500 billion a year.

Reason Magazine's Ron Bailey embraced the Pigou Club, although not by name. Not surprisingly, I found his talk the most sensible.

Marlo Lewis of the Competitive Enterprise Institute took the anti-alarmist view. I thought his best point was when he noted that Fred Pearce's book talks about the catastrophic effects of ice melting by describing the sea level rise that took place when the last ice age ended. Lewis pointed out that there was a lot more ice to melt back in those days. Overall, though, Lewis came across as taking random swipes at the consensus rather than making a coherent case for his point of view.

Pearce himself said, and I agree, that skepticism about climate models should increase one's concern about both tails. That is, the models may under-predict global warming. In fact, that is my number one concern with the issue. His book, which I bought, is a litany of potential disaster scenarios, from peat bogs dissolving and releasing massive amounts of methane to ice sheets quickly breaking loose into the ocean. Even though these scenarios are not in the scientific consensus represented by Dr. McCracken, I think they are the right things to worry about.

Finally, Fred Singer attacked the climate models. His toughest criticism concerned the models' predictions about specific warming patterns in terms of altitude and latitude. He said that the models predicted one pattern, and the data showed a different pattern. McCracken replied that the temperature readings by altitude and latitude were not reliable--which didn't exactly increase my confidence in climate science. Singer also pointed out that one of the leading models forecasts that North Dakota will become a swamp, and another leading model forecasts that it will be a desert. McCracken responded that models are highly non-linear, and small differences can lead to very different results. Again, not exactly a reassuring answer.

Several speakers made self-contradictory statements. For example, Singer said that correlation is not causation, and then later he proudly displayed a chart showing the high correlation between cosmic ray activity from the sun and global temperature. Pearce mocked those who would doubt the scientific consensus for acting as if that consensus were some sort of vast conspiracy, but then his whole outlook is geared toward views that are outside the mainstream.

My sense is that many people in the audience came in with strong views about global warming--one way or the other. My sense is that people left with the same views that they held going in. That is somewhat frustrating. But I plead guilty as anyone else of suffering from confirmation bias. I continue to hold the views I expressed here.


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COMMENTS (5 to date)
Chuck writes:

It contend that the many changes the benefit the environment also benefit the economy. CAFE MPG standards increase productivity alot throught the money saved over mile driven.

Even in the scenario that we factor in these kind of productivity gains when we decide that this or that course of action will cost a net amount of $500 billion, what we don't factor into those models is the cost of being wrong.

To my view, this is a lot like saving money for retirement. I don't know how much retirement will cost, and while it might crimp my lifestyle now to try and be certain to have enough money later, it will crimp my lifestyle a heck of a lot more if I wait until I know for sure how much I'll need for retirement because I'll have to do all my saving at once.

Floccina writes:

We could, if the we decide that reducing the amount of co2 in the atmosphere is a worthy goal, use some of the proceeds of a carbon tax to pay for schemes that get co2 from the atmosphere and sequester it. Terra Preta / agricultural charcoal seems to have promise. We may find that it is far cheaper than we though to be carbon neutral. Not that I think we should act just yet.

Matt writes:

If we decide later that the problem is real, then we have a situation that the temperature rises substantially higher than we would want. To bring the temperature back down requires that we cover damages from the temperature surge.

True, the ice did melt rapidly some 9,000 years ago, and we have underwater cities to prove it. Something like 1/3 of the ice remains. It seems to be receding at 8% per year.

To understand the arctic, think of it as an air conditioning unit. The less ice up there, then the faster it can radiate heat. The hotter we are, the harder the air conditioning unit has to work. To get more efficiency, the air conditioning unit will shed ice.

The problem with the air conditioning system is that it works really hard and the storm intensities from the cold air mass increase. So we are stuck with a quandry. We cannot move to much farther north without sitting in front of this mega air conditioner working way past overtime.

But, even a one degree centigrade rise is about 1/3 above nominal glacial temperatures. So, in the glacial cycle we have little room to maneuver, the cooling unit is up to near 85% capacity, and we are operating at the top of the glacial cycle, not the middle.

Mr. Econotarian writes:

The biggest problem in any climate change response is the naive belief that you can simple "legislate away" carbon.

We have not been able to "legislate away" poverty or drugs for example. This is because most of the efforts in these areas have gone against human psychology (aka economics), and the attempts to get rid of them have often lead to more costs than benefits.

On the other hand, there are known successful interventions in poverty and drugs that lead to actual harm reduction, but they are only due to very careful analysis of the psychology, economics, and politics of the issue. The actual science of the harm played a secondary role.

Atmospheric scientists know a lot about climate, but not a lot about psychology, politics, and economics.

aaron writes:

Chuck, your implication seems to me analogous of a person who, instead of investing 15% of his income for retirement, spends it on enimas in the off chance it will lower his chance of dying of colon cancer by some unknown infitesimally small amout.

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