Friday, July 31, 2009

Understanding Global Warming

There are many ways to do science. One is to observe nature, very carefully, as Jane Goodall did with her chimpanzees. Another is to measure the properties of things in a laboratory. The properties may be the strength of materials, or how a material behaves when it is heated, or any number of qualities that are needed for building automobiles and bridges, for example. Another is to look at what is known about a problem, build a hypothesis, and check out that hypothesis, as in many experiments that are in progress to determine the weaknesses of the AIDS virus that might be exploited to cure those suffering from it; these hypotheses may be about one tiny part of the problem, like how a receptor on a cell surface handles the flow of ions. Yet another is trying to put a number of facts together to form a bigger picture.

This is in contrast to the oversimplified picture of science that seems to be held by members of the press and too many K-12 science teachers. A scientist forms a hypothesis, goes into the laboratory, does an experiment, and comes out with a yes or no answer. Yes supports the hypothesis, no destroys it.

George Will wrote a week or so back about global warming, and James Fallows took the bait. His discussion includes a few posts, linked there, and his selection of reader e-mails. This link seems rather scattered; read all three posts for more coherence.

The climate deniers, like Will, feel that if they find one incorrect measurement, one incorrect calculation, the entirety of global warming is disproved. A public who have learned that oversimplified vision of science is inclined to take such things seriously. But it’s not that simple.

Global warming makes use of all those ways to do science. Observations of sea and land temperatures, gases trapped in glaciers, oxygen isotopes in cave formations, first arrival of migratory birds, extent of sea ice, spring sprouting of plants, and many more are part of the enormous data set. The physical properties, particularly relating to heat and movement, are necessary. Researchers are checking out how smoke particles affect reflectivity and how long they stay in the atmosphere; how ice forms in the upper atmosphere; how much light polar ice really reflects; the interactions between the water in clouds and the other components of the atmosphere, and many more of the individual interactions that make up climate. Putting all this together is the job of the climate modelers, of whom there are many.

Some of the information is wrong, or scrambled, or incorrectly entered into databases. It’s a good sign when those mistakes are found, and one indication that the models are working as they should. The models try to reconcile large amounts of the information; when something doesn’t fit, either the model is wrong or the data is. That’s how the mistakes are found.

Fallows is unhappy that scientists aren’t explaining global warming in an easily understandable way. I’m unhappy about it too, but I haven’t been able to come up with a simple answer because the problem is inherently complex. The scientists, when forced into a sound bite, give their results:
increasing carbon dioxide in the atmosphere will warm the earth unacceptably. We are producing enormous amounts of carbon dioxide by burning fossil fuels. We can stop burning fossil fuels or we can try to capture the carbon dioxide, neither of which is easy to do.
What’s unsatisfying about that is the implicit “Trust me.” Trust is not in long supply these days. Explaining the models, beyond the superficial, is nearly impossible. If you know something about differential equations, you can get a general idea of what’s going on in them. If you’ve actually worked with models like these, you know that cross-checking within and between models and with large data sets is the only way to confirm them, and that it’s reliable. Along with a lot of parameters that can look like fudge factors, this kind of thing activates the trust question. Further explanation seldom helps.

But the problem isn’t confined to global warming. President Obama recently spoke of his difficulty in explaining the issues related to health care.

On the science side, it can be hard to get the experts together and harder to get them to pay attention to the evidence. One expert may say it’s deer that are the problem in spreading Lyme disease, while another says it’s mice. They need to talk to each other. It could be that one or the other is right, or that the deer and the mice interact in such a way that it’s both. Notice that the answer doesn't have to be yes or no.

Doctors can be a breed apart from other scientists. But here are two examples of doctors not wanting to hear the facts, one at a summer camp infected with swine flu, and others who feel that the authority of a lab coat trumps its ability to carry germs from one patient to another. In the nineteenth century, doctors resisted washing their hands when going from one woman in labor to another; when they were finally convinced, the incidence of childbed fever plummeted.

People can be hard to convince. Add into that media that prefer “he said, she said,” and a widespread lack of understanding of science. And there are political-social preferences that might be overturned. That's why, along with the inherent complexity of the subject, it's hard to explain a complex topic like global warming.

Update: Or our media are using their precious time, energy, and money to provide such enlightment as this. I couldn't get through the video, it is so tedious.

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