Humans are not causing global warming.

Myth: Humans are not causing global warming.

Fact: The scientific consensus on global warming is overwhelming.

Summary

There is no dispute about the basic facts of this issue: carbon dioxide is a greenhouse gas; the world's automobiles and power plants pour nearly 6 billion tons of it into the air every year; and there are countless indications that the planet is warming. Perhaps the most revealing is the fact that average temperatures have been gradually rising, and the ten hottest years on record since the 1860s have occurred since 1973.

Argument

In his book, See, I Told You So, Rush Limbaugh misquoted a Gallup poll, claiming that 53% of scientists do not believe that global warming is taking place, 30 percent say they don't know, and only 17 percent are "devotees of this dubious theory." (1) Unfortunately, this is a gross misrepresentation the original poll, which actually found that 66 percent of all scientists agree that global warming has occurred, 10 percent disagree, and the rest are undecided. Rush apparently got his incorrect numbers from a second hand source (either George Will or the National Review) without bothering to confirm them. He has continued to use these false figures despite the fact that Gallup has issued a rare written correction: "Most scientists involved in research in this area do believe human-induced global warming is occurring now." (2)

The scientific consensus that human greenhouse gases are contributing to global warming is quickly growing unanimous. Even the top critics in science have been won over. Thomas Karl -- who has been described as "the darling of global warming skeptics," and whose doubts about global warming have been quoted by conservatives the world over -- has even been swayed by the evidence. One could hardly imagine a clearer warning than the one he gave recently:

The warming now has pretty much returned [after a brief cooling off period caused by Mount Pinatubo, whose volcanic soot temporarily dimmed the sun around the world]. If you were to come back in, say, the year 2000, and if we have taken another jump in temperature [like since 1980], then you are going to see some very strong statements from me and my colleagues. (3) The strong statements of scientists on this issue derive from the catastrophic potential of even a small amount of global warming. The reason why the planet Venus bakes under 900-degree heat is not because it is so close to the sun, but it is trapped under greenhouse gases. Global warming is a serious threat here on earth because it would cause more severe weather, increase the range of deserts, melt the polar ice caps, cause a rise in sea level (which, according to the fossil record, is a major cause of mass extinctions), as well as expand the habitat of deadly tropical diseases.

The only scientific opposition to the global warming theory comes from the expected places: scientific commissions funded largely by the fossil fuel industry, which is responsible for creating the greenhouse gases in the first place. This is highly reminiscent of the all the "scientific" studies produced by the tobacco companies proving that cigarettes do not cause cancer. In a like manner, the industry-backed Global Climate Coalition has mounted a huge public relations campaign to prevent policies that limit fossil fuel use. It issued a report called "Changing Weather? Facts and Fallacies about Climate Change." It completely distorted an important survey issued by Harvard climatologist David Keith, who demanded an immediate retraction of the report. After receiving a blistering response from the world's top climatologists, the Global Climate Coalition issued a watered-down edition of the report, which made no mention of Keith's study. Obviously, even industry-backed scientists are admitting to the evidence.

Although the evidence is not yet 100% certain, it is moving in that direction. Top climatologist Stephen Schneider says, "Is there global warming? I'm not 99% sure, but I am 90% sure." Klaus Hasselmann, of the influential Max Planck Institute for Meteorology in Hamburg, says he is 95% certain that the recent increases in global temperature are tied to human-caused carbon dioxide. Much of the evidence is circumstantial, but it is growing, and becoming increasingly difficult to dismiss. For example:

The ten hottest years in recorded history (since the 1860's, when reliable measurements began) have all occurred after 1973.
Average annual temperatures have gradually been climbing.
The polar caps are melting, and giant cracks are appearing in their enormous ice shelves. An 800-square-mile ice shelf called the Wordie has disappeared from Antarctica. A gigantic iceberg the size of Rhode Island also broke off the Antarctic in January, 1995. If even a tenth of the ice in Antarctica melts, it would raise sea levels 12 to 30 feet around the world. (4)
Forests are climbing farther north into the polar region, thanks to warmer weather and receding glaciers. There has also been a proliferation of plant life in Antarctica.
Disease outbreaks have been increasing all over the world, due to the fact that diseases thrive better in hotter weather.
El Nino seems to be staying longer. (El Nino normally arrives every three years; it is an upwelling of warm water from the deep Pacific Ocean that rises up all along the Western American coast. It usually has a profound effect on weather.) For the last ten years, El Nino has been causing conditions from extreme drought to extreme rain on the West Coast.
Marine animals have been migrating to newer habitats. Creatures who normally live in warm water have been expanding their habitat, whereas creatures who live in cold water have been retreating farther north and south.

The chain of cause and effect here is so brutally simple that it is difficult to see how the Global Climate Coalition can deny it. The fact that carbon dioxide is a greenhouse gas is not in dispute. And the fact that carbon dioxide is being poured into the atmosphere by hundreds of millions of cars and hundreds of thousands of city power plants is also not in dispute. In 1950, these sources poured 1.6 billion tons of carbon into the air worldwide; by 1991, they were pumping about 6 billion tons into the air. (5) And this has been accompanied by all the above signs of a growing heat wave. It is a testimony to the greed of corporate special interests that they would even try to rationalize these facts away.

The United States is by far the largest producer of carbon dioxide in the world. It contributes 21 percent of all the greenhouse gases poured into the atmosphere, ahead of the former Soviet Union, which comes in at second place with 14 percent. To be sure, this is not a proud statistic for capitalism -- at least in its more unregulated form.

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Endnotes:

1. Rush Limbaugh, See, I Told You So, (New York: Simon & Schuster, 1994), p. 180.

2. Steven Rendall, Jim Naureckas and Jeff Cohen, The Way Things Aren't: Rush Limbaugh's Reign of Error (New York: The New Press, 1995), p. 17.

3. Except where otherwise noted, all facts and quotes in this essay are from Charles Petit's article, "New Hints of Global Warming," San Francisco Chronicle, Monday, April 17, 1995, pp. A1, A6.

4. "Ice Cubes for Penguins," Newsweek, April 3, 1995, p. 56.

5. Thomas A. Boden, Oak Ridge National Laboratory, cited by Lester Brown et al. (eds.), Vital Signs 1994 (New York: W.W. Norton & Company, 1994), p. 69.