Though the fear of man-made global warming has come to dominate our cultural discourse, the science behind the scare is looking increasingly uncertain. David Evans is representative of scientists who have become disillusioned with the theory that industrial carbon dioxide emissions are the root cause of global warming: as he points out, the computer models don’t seem to fit the data, while at the same time evidence is mounting in favor of alternative hypotheses, like the idea that climate change may be caused in large part by fluctuations in solar radiation. A series of articles by Lawrence Solomon, who has profiled prominent climate-change dissenters, demonstrates that Evans is hardly alone—and calls into question the often-parroted assertion that there is some sort of scientific “consensus” on the issue (whatever that might mean).
One of Evans’s interesting asides is that “the integrity of the scientific community will win out in the end, following the evidence wherever it leads.” Although this is true in the long run, it’s a bit simplistic. Once a theory gains ascendancy, it may take years or even decades before its adherents are willing to abandon it, even in the face of contradictory data. (See Thomas Kuhn’s landmark book The Structure of Scientific Revolutions for a picture of this phenomenon.) At the most basic level, scientists have their jobs and reputations to think about; it’s only natural to resist the suggestion that one has spent one’s career trying to prove, or solve, a nonexistent problem. No doubt this would be true even in the absence of external pressure. But with the political stakes now so high, scientific integrity is at a decided disadvantage.
In this case, the direct evidence doesn’t support the theory of anthropogenic climate change, so proponents have clouded the issue by seizing on unrelated phenomena in a more or less desperate and blatantly opportunistic way. “Global warming” has reflexively been invoked as the explanation for everything from the devastating 2005 hurricane season (but not the barely noticeable 2006 hurricane season) to the recent proliferation of stray cats. For about two years now, it’s been possible to predict that any report of a noticeable change in the environment or in plant or animal behavior will now be chalked up to global warming, with the implication that we must therefore take some sort of radical action to atone for the sin of carbon dioxide emission.
What’s important to bear in mind is that these observations have absolutely nothing to do with the claim that human activity is causing climate change. Consider, for example, the recent report in the Washington Post that conditions in Greenland are becoming more favorable for cod fishing and agriculture due to a slight increase in average temperature. Oddly, the Post article fails to mention that Greenland must have been just as balmy when it was first settled by the Vikings more than a thousand years ago. Proponents of global warming hysteria prefer to play down this historically inconvenient medieval warm period, explaining it as a local anomaly. Whether or not this is true (and it probably isn’t), how do we know that Greenland’s current good fortune isn’t also a local trend? And, more to the point, if a warmer Greenland is indeed a symptom of global warming, how do we know that human activity is the cause? It’s troubling that questions like these are no longer even asked, because the answers aren’t at all clear.