A View From the Cheap Seats

May 9, 2007

The Other Side of Global Warming – Part 2

Filed under: Environment,Global Warming — trzupek @ 2:41 am


The Othe Side of Global Warming
Part 2: Model Behavior

By: Rich Trzupek
In Part One, we asked the question: Why do advocates of global warming feel the need to browbeat their critics into silence? In my humble opinion, it’s because the global warming case is so weak.

If you’ve got 75 minutes to spare, google “The Great Global Warming Swindle” and watch the video. For the skinny on it, along with some additional facts, read on:

The global warming scare is based on two facts (actual scientific facts, not “scientific consensus”). 1): human activity increases the atmospheric concentration of carbon dioxide (CO2); and 2): CO2 in the atmosphere slows radiative energy transfer, thus warming the earth. In other words, CO2 acts to hold more heat in the atmosphere. Both of these propositions are true, and no legitimate scientist will deny either of them.

So – case closed, right? Cars and power plants do lead to warming! But the actual question is (or should be): Is that warming at all significant? If you burp, does it affect the weather in China? Well, yes, and well, no, not really.

For example, if you own a pet – say a dog – every breath he takes uses up oxygen and puts CO2 into the atmosphere. And if he’s like most dogs, you’ve also got to deal with “tailpipe emissions”, which are mostly methane, a greenhouse gas more potent than CO2.

Of course one dog isn’t going to lead to melting glaciers. Ah, but in the US we’ve got 10’s of millions of dogs, and cats, and gerbils, etc. Added together, they’re putting out a lot more of these gases. Luckily the busybodies haven’t come down on pets (yet) but just wait (can you say PETA?). So, how can we tell if a given source of CO2 is going to cause a significant problem?

A first step is to look at the relative amount of CO2 emitted from a given source. Natural sources like volcanoes put out a lot more CO2 than do human industrial and transport activities (power plants, cars, airplanes, etc.). So does decaying vegetation. And so do animals and microorganisms. All of those natural sources put out much, much more CO2 than human activities. In total, human activity is responsible for much less than 10% of the CO2 going into the atmosphere. And although the US is currently the single major source of that kind of CO2, it’s expected that sometime this year China (Kyoto exempt) will overtake us.

So it’s clear that humans are a minor source of this greenhouse gas. How important is this particular gas in bringing about climate change? It’s not the only factor modifying the climate,, and no legitimate scientist would claim that it is. We now need to look at how much effect CO2 has on the climate, especially in light of the fact that we make a small contribution to CO2 levels in the first place.

CO2 itself is responsible for well less than 10% of atmospheric greenhouse warming (water as vapor and clouds is by far the main factor). So, the net effect of American cars and power plants on global climate through CO2 emissions is – to use a technical term – teeny, in the greater scheme of things.

But, to be fair, let’s accept the idea that upsetting a natural balance, even in a small way, can have effects that are much greater than we expect. How can we tell if that’s the case here?

Fundamentally, there are two approaches: 1) modeling, and 2) studying the climate record. Currently the predicted dire consequences of global warming are based largely on mathematical modeling.

Ask 100 people in a panic over global warming (you can start with Al Gore) to explain modeling, and you’ll get 100 blank stares. That’s because modeling something as complex as the climate is hellishly complicated. To do it thoroughly, you’ve got to include everything from the flux of cosmic rays to the amount of snow cover on the earth’s surface, and dozens of factors in between, and then see how a small change in CO2 affects things. Nobody’s models include all these factors, and nobody is completely sure how to weight the ones that are included. And the ones that aren’t included can be overwhelmingly important: precipitation and storm systems keep the global temperature about 70 degrees F cooler than it would otherwise be for example. (That is, without rainfall and storms, the average temperature of the globe would be about 140 degrees F).

Now consider that we don’t even know the total amount of annual global rain/snowfall – how can we be sure we know how to model it (if it’s even factored in at all)?Trusting these mathematical exercises is an act of faith. That’s not just my view, but that of scientists who (like me) use simpler atmospheric models used in air pollutions studies. Those types of models are much less complex and, unlike climate models, we can look at real-world data to see how accurate those models are. After 30 years of development, the best air pollution models are accurate to within +/- 1%.

There is no way that climate models are more accurate than the best air pollution models. But let’s say that these climate models meet that +/- 1% standard. That translates into an accuracy of +/- 5 degrees when predicting global temperatures. Ready for the punch line? Al Gore and his supporters are using these models to predict climate changes less than that!

A basic principal of science is this: you can’t use a tool to measure something that is less than that tool’s ability to detect. Yet, that’s exactly what Al Gore wants us to do.

It’s also well-known that the models don’t even predict the kind of warming that actually is occurring. The models say that greenhouse warming should be most rapid 10 kilometers up in the troposphere. In actuality, the greatest rate of current warming appears to be at the earth’s surface.

It is scientifically indefensible to claim that climate models can come anywhere close to predicting global temperatures tomorrow, much less 50 years from now. Worse, it’s absolutely irresponsible to make public policy that will affect the lives of billions of people based on a tool that is no more accurate than Madame Zelda’s crystal ball.

But, if we can’t have confidence in the models, we still have the climate record. We can look back and see how CO2 has affected weather over thousands of years. It is the climate record that Al Gore cites as “absolute proof” that humans are going to melt the planet. Not suprisingly, the “inventor of the internet” plays fast and loose with the facts, as we shall see next week.


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