Wednesday, September 5, 2007

Singer on Global Warming: Man-Made or Natural?

In the August issue of Imprimis, there is an essay adapted from a lecture Dr. Singer gave at Hillsdale College-- which in turn was presumably related to his most recent book, Unstoppable Global Warming: Every 1,500 Years. Singer has a Ph.D. in Physics from Princeton, was among other things, the founding director of the U.S. National Weather Satellite Service, and is currently a professor emeritus at University of Virginia and a distinguished research professor at George Mason University.

Excerpts-- with commentary...

OK, here are the primary points in his thesis:

In the past few years there has been increasing concern about global climate change on the part of the media, politicians, and the public. It has been stimulated by the idea that human activities may influence global climate adversely and that therefore corrective action is required on the part of governments. Recent evidence suggests that this concern is misplaced. Human activities are not influencing the global climate in a perceptible way. Climate will continue to change, as it always has in the past, warming and cooling on different time scales and for different reasons, regardless of human action. I would also argue that—should it occur—a modest warming would be on the whole beneficial.

This is not to say that we don’t face a serious problem. But the problem is political. Because of the mistaken idea that governments can and must do something about climate, pressures are building that have the potential of distorting energy policies in a way that will severely damage national economies, decrease standards of living, and increase poverty. This misdirection of resources will adversely affect human health and welfare in industrialized nations, and even more in developing nations. Thus it could well lead to increased social tensions within nations and conflict between them.

Framing the scientific question...

The most fundamental question is scientific: Is the observed warming of the past 30 years due to natural causes or are human activities a main or even a contributing factor? At first glance, it is quite plausible that humans could be responsible for warming the climate....But in seeking to understand recent warming, we also have to consider the natural factors that have regularly warmed the climate prior to the industrial revolution and, indeed, prior to any human presence on the earth. After all, the geological record shows a persistent 1,500-year cycle of warming and cooling extending back at least one million years.

On the purported "scientific consensus" on one thesis within the debate:

In identifying the burning of fossil fuels as the chief cause of warming today, many politicians and environmental activists simply appeal to a so-called “scientific consensus.” There are two things wrong with this. First, there is no such consensus: An increasing number of climate scientists are raising serious questions about the political rush to judgment on this issue. For example, the widely touted “consensus” of 2,500 scientists on the United Nations Intergovernmental Panel on Climate Change (IPCC) is an illusion: Most of the panelists have no scientific qualifications, and many of the others object to some part of the IPCC’s report. The Associated Press reported recently that only 52 climate scientists contributed to the report’s “Summary for Policymakers.”

Likewise, only about a dozen members of the governing board voted on the “consensus statement” on climate change by the American Meteorological Society (AMS). Rank and file AMS scientists never had a say, which is why so many of them are now openly rebelling. Estimates of skepticism within the AMS regarding man-made global warming are well over 50 percent.

Ouch! That sounds similar to the results you'd get from asking social scientists to weigh in on economic questions.

The second reason not to rely on a “scientific consensus” in these matters is that this is not how science works. After all, scientific advances customarily come from a minority of scientists who challenge the majority view—or even just a single person (think of Galileo or Einstein). Science proceeds by the scientific method and draws conclusions based on evidence, not on a show of hands.

Nice point a la Thomas Kuhn's seminal work, The Structure of Scientific Revolutions...

But aren’t glaciers melting? Isn’t sea ice shrinking? Yes, but that’s not proof for human-caused warming. Any kind of warming, whether natural or human-caused, will melt ice. To assert that melting glaciers prove human causation is just bad logic.

A basic point, but still important to note. Now, on the use and limits of empirical/statistical models, especially if misunderstood or misapplied...

The fact that the observed and predicted patterns of warming don’t match indicates that the man-made greenhouse contribution to current temperature change is insignificant. This fact emerges from data and graphs collected in the Climate Change Science Program Report 1.1, published by the federal government in April 2006 (see It is remarkable and puzzling that few have noticed this disparity between observed and predicted patterns of warming and drawn the obvious scientific conclusion.

Now, on natural factors that contribute to global warming...

A quite different question, but scientifically interesting, has to do with the natural factors influencing climate. This is a big topic about which much has been written. Natural factors include continental drift and mountain-building, changes in the Earth’s orbit, volcanic eruptions, and solar variability. Different factors operate on different time scales. But on a time scale important for human experience—a scale of decades, let’s say—solar variability may be the most important.

And finally, back to the political implications of the "science" and the science of global warming. Here, Singer echoes what I posted from Thomas Sowell a few days ago on "trade-offs" and the importance of rigorous and objective cost/benefit analysis.

The nations of the world face many difficult problems. Many have societal problems like poverty, disease, lack of sanitation, and shortage of clean water. There are grave security problems arising from global terrorism and the proliferation of nuclear weapons. Any of these problems are vastly more important than the imaginary problem of man-made global warming. It is a great shame that so many of our resources are being diverted from real problems to this non-problem. Perhaps in ten or 20 years this will become apparent to everyone, particularly if the climate should stop warming (as
it has for eight years now) or even begin to cool.


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