Tuesday, May 13, 2008

Skeptic Magazine Pokes Holes in Global Warming Models

Lubos Motl, the Czech string theorist and blogger, noted that in Russia, they don't really care about global warming, and Russian scientists are not stupid. He thinks this is because they aren't influenced by Western political correctness, a nice contrast to the politically influenced Russian scientists during the Cold War. And of course its not just political correctness: the US gives about $2B a year to study global warming, which means a lot of objective scientists are paid to basically come up with studies that support the hypothesis. That's a lot of money, and it's naive to think this doesn't influence the findings.

I think that since 85% of Americans believe the standard global warming story (it's anthropogenic, and threatens the Earth), given the sheer stupidity of the average American, that's reason enough to be skeptical. Consider that only 75% of Americans believe OJ killed his wife, and only 67% of American believe the US was NOT involved in 9/11, I think this kind of majority for a much more nonobvious fact indicates the 'facts' are not dominating the public debate, because isn't OJ's guilt more obvious than Global Warming? That is, the models that generate the scary anthropogenically caused global warming scenario are so complicated, how could so many Americans be so certain?

Part of it is the simple story. CO2 is a greenhouse gas. Cars and such create CO2. Ergo, more CO2, more warming. It's like Y2K, which was so plausible because the story was simple enough to explain to 60 year old executive (who had never coded in his life). But CO2 is only 0.036% of the atmosphere, and that is only 15% of the greenhouse gasses (water vapor and methane being the most). As humans only produce 2% of the CO2 annually (most is from water evaporation), I think its reasonable to assume that the natural variability of CO2 makes it difficult to assert that human activity is directly causing the temperature increase. After all, historically, you can't really infer from ice core samples whether the CO2 temperature relation is driven by the temperature causing CO2 to rise (say, via a Milkankovitch cycle), or vice versa. Further, there is the natural variability in the other greenhouses gases. For example, a one percent change in water vapor does the same thing as doubling the carbon dioxide in the air, and water vapor can vary by a factor of 2 day to day, so I'm sure it varies at the scales that matter for these doomsday scenarios. Then there's the CO2 mechanism. CO2 absorbs all radiation available to it in 10 meters. More CO2 only shortens the distance. Either way, anything that can be absorbed by CO2 is already being absorbed.

There are lots of positive and negative feedback loops in an ecosystem like the Earth. Given the persistence of life over hundreds of millions of years, one should think there are many more negative feedback loops (dampening effects), because if we were always on this unstable inflection point, we should see massive extinctions every million years. But the global warming alarmists just assume that the system is mainly full of positive feedback effects (wikipedia mentions 7 feedback loops on their website; 6 are amplifiers).

Anyway, Skeptic Magazine has a neat article on Global Warming, and they note that the current Global Warming Models greatly understate their uncertainty, because the standard errors refer merely to the model's errors--assuming they are true. That is, no uncertainty due to parameter uncertainty, or functional form uncertainty. The author estimates that the uncertainty in the part of the model that addresses cloud cover generates a 100 degree uncertainty band over 100 years. That's right, 100 degrees. With this much uncertainty inherent in these models, for this one aspect, one could reasonably assume these models are pretty worthless for long-run forecasting.

Indeed, to give an example of the uncertainty in the system they are modeling, consider that global temperatures have increased by 0.6°C this century. How much is due to human-based CO2? Maybe 0.2°C. Now compare that to natural variations. Seasonal variations are typically 20°C. Localized effects vary wildly between the equator and poles. Then there are random variations in such things as the Gulf Stream in the Atlantic Ocean which heats Europe, and El Nino which affects the US. But supposedly, out of that maelstrom, climate scientists can deduce the human-created CO2 is sufficient to take us to a tipping point. It's like saying, if you eat that French Fry, you're going to die. Uh huh.

Models are maps of reality, not reality. Often they capture a select subset of what is going on, and so have little overall relevance. For example, the major 7 money center banks in the US had annualized 99% VaRs of about $1.8B in 2007, but still managed to lose an average of $42B in market value over the past 12 months. Now, either their models were really wrong, or, more likely, they weren't that bad, they just excluded a lot of really important stuff (you should read the fine print by the asterisks). Such models are often useful in piecemeal application, but until one can demonstrate realistic, out-of-sample correlations on meaningful applications, they should be applied and discussed piecemeal.

10 comments:

Teresa Lo said...

Consider how many Americans believe in ... God:

"Fully 92 percent of Americans say they believe in God, 85 percent in heaven and 82 percent in miracles, according to the latest FOX News poll." -- Fox News 2004

"America's commitment to religion is even more striking when measured against other nations. Nine out of 10 Americans say they believe in a personal God; in Denmark and Sweden, the figure is only one in five. More than six in 10 Americans express unequivocal faith that there is a God, agreeing that "I know God exists and I have no doubts about it." When that same question was asked in the 1991 International Social Survey, fewer than a third of those surveyed in Great Britain, what was then West Germany, New Zealand and Austria, for example, expressed similarly unshakable faith." -- Washington Post, 1998

"The poll of 2,455 U.S. adults from Nov 7 to 13 found that 82 percent of those surveyed believed in God, a figure unchanged since the question was asked in 2005.

It further found that 79 percent believed in miracles, 75 percent in heaven, while 72 percent believed that Jesus is God or the Son of God. Belief in hell and the devil was expressed by 62 percent.

Darwin's theory of evolution met a far more skeptical audience which might surprise some outsiders as the United States is renowned for its excellence in scientific research.

Only 42 percent of those surveyed said they believed in Darwin's theory which largely informs how biology and related sciences are approached. While often referred to as evolution it is in fact the 19th century British intellectual's theory of "natural selection." -- Reuters, 2007

"Most Americans do not accept the theory of evolution. Instead, 51 percent of Americans say God created humans in their present form, and another three in 10 say that while humans evolved, God guided the process. Just 15 percent say humans evolved, and that God was not involved." -- CBS News, 2005

Amazing, eh?

ed said...

I think you're right to be skeptical about the models and about much of the public rhetoric, but I think you're just wrong when you say:

"it difficult to assert that human activity is directly causing the CO2 increase"

The increase in global temperatures over the last century has been small and inconsistent. By contrast, the increase in atmospheric CO2 over the same period has been steady, very large, and seemingly unprecedented. I think it's hard to believe that this increase is NOT caused by human industrial activity.

Furthermore, doesn't uncertainty about the effects of CO2 actually STRENGTHEN the case for action, the same way volatility increases the value of a put option?

Eric Falkenstein said...

tlo: Don't diss religion too much. Its essential for the lower half of the bell curve, in my elitist opinion. Because for someone with a short time horizon, who can't comprehend 'rational long term self interest', reading about the Golden Rule and not coveting your neighbor's ass--under threat of eternal damnation--is salubrious.

ed: That's a good point on the CO2 has risen more steadily than temp over the past century, so that if temp increases cause CO2 to rise, that's a strike against that theory. I can’t explain why I wrote that, I think I meant temp increase and changed accordingly.

But I disagree on the option analogy. If uncertainty says that we are either going to +100 or -100 shifts in temp, whatever we do now doesn't matter, or we can't estimate it will matter. And that includes doing good or bad things. Of course, there's more reason to not pollute than global warming.

gabe said...

this can go both ways. if some scientific studies are biased by the $2B in grants, how much do oil companies pump up in the rest of the community to provide the numbers you use? I'd say it cancels out.

maybe these positive feedback loops do happen. didn't they say recently we were close to extinction (some 2k humans left in the world) few hundred k's years back?

anyhow both sides pull numbers out of their collective a*s, but why take the chance? for some .1% extra GDP growth? bernie will take care of that in an instant.

J. said...

...not coveting your neighbor's ass...

What?

Anonymous said...

Wow. You're not just an expert on finance, but on climatology. Nice use of the word "anthropogenic"; I like to throw that one around as much as possible, like when explaining how a dent appeared in the bumper to my wife.
Perhaps people believe in Global Warming not because of the greenhouse gases, but because it seems intuitive that if we take energy stored in the earth over millions of years and release it in a few hundred, it will get hot. Because they know that if they put their hand on their engine after driving around, it will get burned. And if you multiply that by 1 billion, you get a lot more heat.
I believed you when you debunked the relationship between risk and return. Appreciate the insights on Climate Change. But I'm afraid that next you will tell us there weren't any WMDs.

Eric Falkenstein said...

Clearly, the fun of a blog is getting to vent on things outside one's area of expertise. I'm not a climate expert, but then foremost global expert Robert Hansen is an astronomer, so lots of 'experts' are merely 'smart'. Anyway, I reference my opinions with facts, and so such assertions should stand on their own, not based on my credibility, which in this area is admittedly small. I could be wrong.

j: commandment #10 "You shall not covet your neighbor's house. You shall not covet your neighbor's wife, nor his male or female slave, nor his ox or ass, nor anything else that belongs to him."

Anonymous said...

When humans create a model of the earth that allows them to be able to predict the future, we'll be able to build a new earth from scratch.

That wouldn't be a miracle, but it would sure look Godly.

I heard someone say, "I don't know God."

I replied, "but I know you."

What would God do?

Eradicate disease?
Done that.
Re-engineer the gene to promote growth?
Done that.
How about re-engineer the Earth?

Too late.

We already did that too, and the effects are coming back like DDT in meltwater to challenge the penguin all over again.

Long term is longer than we thought.

Ever heard of a drug being recalled because it caused all of the daughters to be infertile?

DES. Morning sickness pill.

That drug has been recalled, but how many more are still being consumed because the threat has not been predicted yet?

Plastic that forces estrogen production still being used as infant bottles?

By definition, Gods impact.

What did Edison or Tesla do? Sit around discussing whether AC or DC? No they fried cats alive and illuminated lights without wires.

Gods don't argue about whether they can impact something, all the while tearing it apart to consume its pieces.

You have done nothing but impact your environment your entire life.

Some Gods have deadly impact. Oppenheimer and Teller.
Fission and fusion.

Some like Norman Borlaug

http://www.reason.com/news/show/27665.html

just feed the planet all by themselves.

What was your impact? Godly? Crawdadly?

Earl E

Anonymous said...

I think Eric's arguments would be stronger if he could find examples of when 90%+ of academic scientists (not just climatologists) supported a scientific theory that later turns out to be widely rejected. (Socialism doesn't count.)

My personal opinion is that humans cause global warming (P=0.8) but that any currently proposed intervention is not cost effective (P=0.95).\

sbvor said...

There is a great deal more I can and will (later) post on this topic. For now, you may find these two posts (and associated sub-links) of interest:
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CO2 is Not a Problem
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The Current Cooling Trend
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