Is Science Behind the Times?

December 30, 2003 • Commentary

Everyone who reads Science — the journal of the lobbying organization the American Association for the Advancement of Science (AAAS) — knows that it only accepts one side of the global warming story in its “Compass” and “Perspectives” sections, and in its more opinionated, mainline articles. Anyone who writes otherwise for those sections gets a quick rejection. That’s understandable because global warming is scheduled to pay U.S. scientists about $4.2 billion next year, and the AAAS is just doing its job keeping the customers happy.

But sometimes they go a little overboard in their one‐​sided zeal, particularly when they schedule so‐​called bombshell articles to coincide with the periodic meetings of the signatories to the United Nations’ Climate Change treaty, discussing implementation of the (dead?) Kyoto Protocol. The most recent case of this funereal dance just ended in Milan, Italy.

For Milan, Science published, and then heavily publicized, an article by federal climatologists Tom Karl and Kevin Trenberth, entitled “Modern Global Climate Change.” This reveals that Science, in its plumping for Kyoto, is now publishing material that is decades behind the global warming power curve.

Karl and Trenberth repeat the usual United Nations saw that there’s “a 90% probability interval for warming from…1.7° to 4.9°C” in the next century.” In fact, the 21st century warming rate is now well‐​known to be confined to a much lower and smaller range, about 0.75 +/- 0.25°C per 50 years, and may be lower than that.

You can’t even generate a constant rate of global warming unless carbon dioxide goes up exponentially. In other words, a constant increase in carbon dioxide must lead to a damped (slowing) response in warming. This has been known since 1872.

Karl and Trenberth give the impression that this exponential increase is happening. It’s not. But, they write: “Recent greenhouse gas emission trends in the United States are upward, as are global emission trends, with increases between 0.5 and 1% per year over the past few decades.”

The problem here is one of purposeful imprecision, as in “past few decades.” In reality, data from the Energy Information Administration show that there was some substantially exponential growth in emissions, but since 1980 it’s been much closer to a simple linear change. Twenty‐​four years of recent linearity comprises “a few decades,” doesn’t it?

This change in emissions is reflected in changes in the growth rate of atmospheric carbon dioxide, which stabilized nearly 30 years ago. That’s right. While all scientists have glibly assumed an exponential increase in atmospheric carbon dioxide, that stopped, in the statistical sense, three decades ago. But an exponential increase is required to generate a constant rate of warming.

What happened? Per capita emissions of carbon dioxide peaked around 1980 and have been in statistically significant decline ever since.

What perpetuates the tired myth of exponentially increasing carbon dioxide? It’s the oft‐​repeated saw that “Everyone in the world aspires to a U.S. lifestyle.” Since we used to emit about 30 percent of the world’s industrial belching of CO2, the math becomes obvious if everyone emulates us.

People who assumed increases in per capita carbon dioxide were wrong 25 years ago and they are wrong now. But this is precisely what is input into every general circulation climate model, and these models serve as the basis for Karl and Trenberth’s projections for warming. They’ve been run with the wrong data for a quarter century!

If you put in the right data, warming drops dramatically, to about 1.6°C in the next 100 years. A while back, in a statement he would probably like to have back, Robert Watson, then head of the U.N.‘s Intergovernmental Panel on Climate Change, allowed that such a small warming might actually be beneficial.

Why was everyone wrong? Well, it turns out that the world is largely emulating the United States. Per capita incomes are increasing. As they increase, per capita emissions drop because people can invest in more efficient technology. In what large nation did the drop first take place? The good ‘ole USA.

How on earth did Science become so derriere in the face of so much reality? Perhaps that’s what happens when one’s political goals get in the way of one’s science.

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