Global warming is a fact

The recent column by Larry Tradlener (Feb. 2) makes several statements regarding science and global warming that are erroneous.

He claims consensus among world scientists about global warming, because consensus is not science. Of course it is not science; it is agreement based on highly credible scientific evidence that global warming is most likely man-made. Does he think scientific credibility is determined by popular vote?

Mr. Tradlener’s definition of science is incomplete. The most important activity of science is its creation and testing of theories that explain the experimental data. The most probably theory for global warming is emission of CO2 from human use of fossil fuels. Mr. Tradlener states, “There is no scientific proof of man-made global warming!” it is impossible to prove any theory. There is no certainty, only more or less probability, depending on the quality and quantity of the evidence. Gravity, the atomic-molecular structure of matter, relativity, evolution by natural selection, e.g., are theories, as is man-made global warming. The use of the phrase, “It’s only a theory,” by global warming deniers simply demonstrates their ignorance of science. While theories cannot be proven, they can be, and often are, falsified or modified by new evidence.

Mr. Tradlener states, “What we do know is that the people involved in the ‘study’ (of global warming) lied about their findings.” Since thousands of scientists in many laboratories are involved in these studies, this is clearly false. And what evidence does he have that anyone lied? Many other scientists have followed the science in reviewed journals (such as Science and Nature) and find the evidence convincing, as do I. So who are the “we” in his statement? The Republican presidential candidates, none of whom have any scientific credentials, but who loudly proclaim global warming is “junk science”? Or the small number of scientists who deny man-made warming but have not published any articles in peer-reviewed scientific journals supporting their views?

Who are the deniers? In addition to the few scientists in this category (some of whom receive funding from oil, coal and energy corporations), a significant number are economists with no apparent formal training in science. The Danish economist Bjorn Lomborg, e.g., is a current favorite with the global warming skeptics. Lomborg admits global warming is occurring, but not to worry, it will be small, and adaptation by humans will be easy (Bjorn Lomborg, The Skeptical Environmentalist, Cambridge Press, 2001). This book has received unfavorable critical reviews by forums of scientists and in Scientific American, 286, 61-72, 2002. More recently, a devastating critique (Howard Friel, The Lomborg Deception, Yale University Press, 2010) details Lomborg’s many errors and deliberate misuse of references, hence the title.

Global warming manifests itself in many ways: increase in global temperature, loss of summer ice in the arctic, retreat of glaciers world-wide, acidification of the oceans, partial loss of the west antarctic ice shelf, increase in severity of storms, among other effects. Perhaps the most alarming is the steady increase in CO2 levels in the atmosphere from pre-industrial levels to the present. We have accurate records of CO2 levels in the pristine air on Mauna Loa in Hawaii from 1957 to 2010, thanks to the scientific work of David Keeling (the Keeling Curve), which indicates it has risen from approximately 300 ppm to 395 ppm over this period, an increase of 32 percent. Measurements from the last several years also indicate the current increase is non-linear, averaging 3 percent a year. Assuming the annual increase remains constant, calculations indicate it will rise to 532 ppm by 2020. As third-world nations pursue industrial growth and world population increases, it is likely the rate of increase will climb, unless limits to the use of fossil fuels are vigorously pursued world-wide.

James Hansen, director of the NASA Goddard Institute for Space Studies, perhaps the nation’s leading scientist on climate studies, has proposed the CO2 concentrations should be reduced to 350 ppm to avoid the serious consequences of global warming, requiring the phase-out of most fossil fuels as soon as possible (James Hansen, Storms of My Grandchildren, Bloomsbury USA, NY 2009).

Global warming is a fact. Among scientists, the theory of man-made origin by the use of fossil fuels is highly probable. The consequences, if ignored, are likely to be serious indeed.

Jack Spence is a retired scientist and university professor. He lives near Dolores.

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