Arnold Kling  

Global Warming and Models

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Richard S. Lindzen writes,


Even if we attribute all warming over the past century to man made greenhouse gases (which we have no basis for doing), the observed warming is only about 1/3-1/6 of what models project.

His point is that the models generally tend to predict more global warming than what we have observed, so that they are inherently alarmist.

My view is not so much that the models are biased in one direction or another (I cannot claim any expertise in that area), but that there is simply not enough data relative to the complexity of the process to have any confidence in a model. I would not be surprised if, as Lindzen implies, global warming proceeds more slowly than the models project. However, I also would not be surprised if the errors are in the opposite direction.


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TRACKBACKS (3 to date)
TrackBack URL: http://econlog.econlib.org/mt/mt-tb.cgi/543
The author at Cafe Hayek in a related article titled Reality-Based Skepticism of Government Action to Fight Global Warming writes:
    Members of the true reality-based community understand that atmospheric science does not give the final answer about what, if anything, governments should do to combat global warming. The earth’s temperature might well be warming, and human commerce ... [Tracked on August 13, 2006 8:29 AM]
COMMENTS (8 to date)
Al Fin writes:

That's beside the point, really. Why aren't the big investors betting on global warming? Because there is no consensus, scientifically, just like Lindzen says. The hotshots of climatology are raking in the grant money, but only if they toe the line of greenhouse gas driven global warming.

Honestly? Anyone with training in science, no matter what the field, could take a look at the climatological data and come to the same conclusion Lindzen does. Global warming is a political slamdunk as long as the media stays on the bandwagon. It's never been a scientific slamdunk.

Max writes:

And you do have scientific background to proclaim something like that? Just asking...

James writes:

Al, forgive my failure of imagination, but what would you recommend as an investment if I believed there would be a lot of global warming in the future? The things that seem like they would pay off are also terribly sensitive to any future regulation imposed in response to future warming.

paul writes:

I can think of two:

buy land in Canada

sell ocean front property

seriously, Al Fin is right. the rational response to global warming isn't to stop growth but to reallocate resources and if you can't think of how to reallocate then maybe the problem isn't obvious.

Dezakin writes:

"sell ocean front property"

This still is risky. Ocean front property is a bad deal now, but prices still are going up even with rising insurance premiums. The market doesnt behave as rationally as classical minded folks would have us believe.

The politics of climate change often totally obscure the real debate. Theres all the talk about whether or not climate change is occuring which we can say with reasonable certainty it is.

Theres whether or not its anthropogenic, but the truth is it doesnt matter if it is or isn't. It only matters if we can do anything about it and what the costs and benifits of climate change mitigations are. We dont know so we cant rationally act to do anything, and the best thing to do is what we've allways done.

The one exception to that is where the mitigations are free. Prohibiting new municipal coal electric power generation is essentially free provided we remove all legal obsticles for minicipal nuclear power generation. Nuclear can compete on cost with coal, and frees coal up for synthetic fuel production.

RogerM writes:

GW is a good field for economists to get invovled in because of its reliance on modelling. One real problem with the models is that they have never been validated, much like many of the macro econ models. The scientific community tried to validate them in the late 80's, but they failed so badly that the issue was dropped until recently. Then another effort began several years ago to validate the top models, but instead of validating against temperatures, they chose some obscure weather patterns to validate against and, guess what, they did quite well. Until the scientific community gets around to validating their models against temperatures, no one should take them seriously.

Concerning CO2 and GW, the charts of past CO2 levels and temperatures are widely available on the internet. There's a strong correlation between the two. High CO2 levels go together with higher temps. I have two problems with the conclusions drawn from this data. 1) What caused the huge swings in CO2 before industrialization and 2) why are the movements in CO2 and temperature simultaneous? I would expect CO2 increases to lead temperature if CO2 accumulation caused temp increases. That they occur simultaneously suggests to me that they are both effects of another cause.

jb writes:

I will say that, for me, the glaring problem with the Global Warming consensus is the lack of consensus on cloud cover impact. (see the Wikipedia article here: http://en.wikipedia.org/wiki/Global_warming. - Scroll down to Climate Models) That seems (to me) to be a huge problem for any sort of realistic simulation/predictive model, since we know that cloud cover is both an insulator and a shader.

If I understand my global warming physics properly, the anthropogentic forcing of CO2 is, by itself, not that big of a deal. But the increase in CO2 causes an increase in water vapor (evaporation), which is a big deal, because water vapor is the primary greenhouse gas.

All fine and good so far. But then, what does the additional water vapor in the air do? Well, generally people believe it will increase the cloud cover. Ok, I'm with you. Then what.

Then.... nothing. No solid agreement on what will happen with increased cloud cover - will it cause a cooling effect, a warming effect or what? No one seems to know. And Lindzen says this, and he gets raked over the coals by the people at realclimate.org, who seem to have no tolerance from anyone, no matter how well credentialed, who disagrees with their dogma.

Now, it is perfectly reasonable to believe that they (realclimate.org) think they are trying to save the earth, and their critics (like Lindzen) are wasting valuable time. But at some point, I worry about this anthropogenic forcing of GW consensus, and what impact these abnormally high levels of consensus emissions will have on the "academic ecosphere". I've done some modelling, and based on my forecasts, we can expect a significant (+4C) increase in academic condescension over the next 100 years if this situation is not reversed. Only a stringent plan to limit the emissions of individual academics, combined with careful monitoring of, and proper sequestering of existing academics will alleviate this Condescension crisis. Indeed, some feel it is already too late, and we've reached a positive-feedback loop of ever-increasing Condescension on a global basis, one that will inexorably lead to a world dominated by choking, suffocating smug - a perfect storm of self-satisfied academics telling us all how to live our lives according to their pseudo-scientific personal biases.

And call me crazy, but that's just something I don't want to see happen. Because I truly care about the future of our Earth.

Mr. Econotarian writes:

The biggest risk of global warming is global regulation.

We have good evidence of very rapid natural environmental shifts on the Earth in the past which were very disruptive to life. It is very possible that there is an anthropomorphic environmental change going on right now as well, but since we know nature can do the same thing, perhaps we should worry more about how to survive massive climate change rather than figure out how to stop humanity's attempt at doing what nature has regularly done.

In particular, we know that rich people survive environmental challenges better. Rich people have better access to environmental warning systems (tsunami warnings, hurricane warnings, etc.), rich people have better access to transportation (bikes, cars, ec.), have better access to heating and cooling solutions, and have better access to food supplies.

The way for humanity to be environmentally survivable is to become rich. This is a key issue which needs to be balanced against real or theoretical environmental changes due to humanity becoming rich.

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