Of Climate Models and Hurricane Predictions

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The climate models used to construct predictions for anthropogenic contributions to climate change are completely different to those used for predicting the activity of hurricane seasons. Not least because the activity of a given hurricane season is governed by many factors, or which only one is 'global warming'.

It's also worth noting that the guy at NOAA who actually does the hurricane predictions is a certain William Gray, who is a vehement AGW skeptic.

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Completely wrong about Gray in that he doesn't work for NOAA and is often critical of them.

Wrong about NOAA as well and their climate models. From one of the links I posted:

Wind shear is one of the dominant controls of hurricane activity, and the models project substantial increases in the Atlantic," said Gabriel Vecchi, lead author of the paper and a NOAA research oceanographer at GFDL. "Based on historical relationships, the impact of the projected shear change could be comparable in magnitude as that of the warming oceans—with the opposite effect."

Examining possible impacts of anthropogenic greenhouse warming on hurricane activity, the researchers used climate modeling to assess large-scale environmental factors tied to hurricane formation and intensity. They focused on projected changes in vertical wind shear over the tropical Atlantic and how those changes tie to the Pacific Walker circulation. The Walker circulation is a vast loop of winds that influences climate across much of the globe, and varies during El Niño and La Niña oscillations. (Click NOAA image for larger view of the Pacific Walker Circulation. Click here for high resolution version. Please credit “NOAA.”)


Here's another linky that discusses NOAA climate models and the effects on the climate of quadrupling CO2 emissions:

Climate Impact of Quadrupling CO2


An overview of GFDL climate model results is presented from a series of experiments examining the possible climate impact of a quadrupling of atmospheric CO2. Much of the recent anthropogenic climate change research has been focused on the issues of climate change detection and projections of climate change over the next century. On the other hand, analyses of future emission scenarios in the IPCC and elsewhere indicate that on a multi-century time scale, CO2 levels are likely to rise well beyond a doubling unless very substantial emission reductions occur. Therefore, longer term aspects of climate change, based on higher-than-doubling CO2 levels, are becoming an increasing part of the debate. In this report, the possible climate impacts of a CO2 quadrupling are examined.



Thanks for playing though.

[Arp220]

Hmm, could have sworn Gray worked at NOAA at one point. Oh well.

As for your second point - the models used to study AGW are generally one of a class of models called coupled ocean-atmosphere general circulation models. These models are not used to predict the severity of hurricane seasons. Neither of the links you give relate to these class of model.

Just out of interest - is it your contention that AGW is negligible and/or will not happen? Thats AGW and not GW, by the way. If so, I have a little proposition for you.

[adios]

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Hmm, could have sworn Gray worked at NOAA at one point. Oh well.

As for your second point - the models used to study AGW are generally one of a class of models called coupled ocean-atmosphere general circulation models. These models are not used to predict the severity of hurricane seasons. Neither of the links you give relate to these class of model.

Just out of interest - is it your contention that AGW is negligible and/or will not happen? Thats AGW and not GW, by the way. If so, I have a little proposition for you.

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What is negligible vs. significant? My arguments are:

In their current state, the predictive value of climate models is unproven.


The second argument I'm making is that climate models will improve significantly over time and will evolve. In expect that we can't imagine the improvement that will take place over the next 50 years.

Third argument is that people are putting way too much stock in what climate models in their current state are predicting.

Fourth argment is that politicians are exploiting the situation to promote their own agendas.

Fifth argument is that the conditions for 3 and 4 are a disaster for funding research.


wacki doesn't seem to want to address them, what do you think?

Also does this qualify me as a skeptic, a non skeptic, or something in between?

[Phil153]

Since wacki is busy (and probably bored with this) I'll have a stab.

In their current state, the predictive value of climate models is unproven.

As an assertion this is a failure as it fails to quantify anything. It also seems dubious. Weren't the climate models used on past data? I believe that's one of the many criteria for any of the many models to be taken seriously. Haven't the predictions of the climate models from last century held up in the last 8 or so years?

If climate models are so inaccurate or useless, why do they all show the same trend and similar ranges, even though the underlying algorithms are quite different? Why has no one come up with a climate model that works accurately on past data and predicts no temperature increase?

Your criticism of the models lacks depth.

The second argument I'm making is that climate models will improve significantly over time and will evolve. In expect that we can't imagine the improvement that will take place over the next 50 years.

Sure...but that doesn't mean the current models will be proven wrong. The most likely scenario, imo, is that the error ranges of the current models will narrow as precision increases. #2 is neither here nor there as relates to this debate.

Third argument is that people are putting way too much stock in what climate models in their current state are predicting.

Exactly how much stock should we be putting into it? If the eight or so more accurate models on past data, using different underlying physics and algorithms, all come to the same conclusion, are you suggesting we should be ignoring them? Exactly how much stock do you think we should be putting in these models?

Fourth argment is that politicians are exploiting the situation to promote their own agendas.

How does this relate to the truth or otherwise of the science? As far the IPCC goes, the main role of politics is to water down the scientific conclusions to make them more palatable to governments who have to sign off on the report.

Fifth argument is that the conditions for 3 and 4 are a disaster for funding research.

You'll need to elaborate on why this matters.

[Arp220]

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What is negligible vs. significant? My arguments are:


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Lets say... 'less than 5%'

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In their current state, the predictive value of climate models is unproven.


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I suggest looking at the IPCC report a little more closely. In particular the section where GCMs are used to construct historical temperature records. They don't do too badly.

I suppose by definition a model is 'unproven' until the events it is predicting either do or do not happen, but that is not the sole arbiter of a models predictive power. Otherwise, no-one would ever use them [img]/images/graemlins/smile.gif[/img]

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The second argument I'm making is that climate models will improve significantly over time and will evolve. In expect that we can't imagine the improvement that will take place over the next 50 years.


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This is true, however it's no reason to ignore the models that exist now. You'd never do anything if you just said 'oh wait 50 years, things will be better'

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Third argument is that people are putting way too much stock in what climate models in their current state are predicting.

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The scientists certainly are not. What the media do is their business.

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Fourth argment is that politicians are exploiting the situation to promote their own agendas.

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They do this with EVERY situation. What's different about this one?

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Fifth argument is that the conditions for 3 and 4 are a disaster for funding research.


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If you're referring to the Bush administrations reprehensible desecration of funding research, and indeed science generally, then I agree with you.

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Also does this qualify me as a skeptic, a non skeptic, or something in between?

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Difficult to say at the moment.

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Quickly, in their current state I don't think we have enough data to make many conclusions about climate model predictions.

I never said that we shouldn't use them, in fact I've said the opposite.

wacki is right that computing power has to increase in order to provide more "fidelity" but I also strongly believe that we have not identified all of the variables accurately that make up a comprehensive climate model. I think as time passes we will.

As far as politicians see my response to wacki. The gist of which is that public policy is being formulated and acted upon. If that policy is such that special interests get to line their pockets at the expense of John Q. Citizen then I think that we would all agree that we don't need that. I am of the believe that is precisely what's happening now. It's one thing to say yeah there's a problem that needs to be addressed. It's quite another thing to actually address the problem.

As far as funding, I think that overblown expectations lead to pessimism and distrust which leads to lack of interest. Not saying the Bush administration gets a pass either. Just saying that the lack of funding is not seen by the public as a bad thing.

I think the word skeptic is often used perjoratively and thus is polarizing. There is a middle ground IMO.

Welcome to the forum [img]/images/graemlins/smile.gif[/img] and thanks for your reasonable reply.