SCIENCE MATTERS by David Suzuki
After hurricanes Katrina and Rita plowed swathes through the southern US, most people were probably wondering how to help those in need, and were saddened by the destruction wrought. Some, however, were more concerned with getting another message out: “It has nothing to do with global warming!”
Within days of Katrina’s strike, several Canadian newspapers published one writer’s op-ed, describing how it has become “fashionable” for governments, environmental groups, and those in the media to blame extreme weather, like hurricanes, on climate change. The author went to great pains to insist that there is no connection between the two.
Strange. I can’t recall a single headline that read: “Hurricanes hit US – global warming to blame.” Nor can I recall any remarks made by any environmental groups attributing the disaster to global warming. Fact is, no editors wrote such headlines, and no scientists or representatives from environmental groups cited climate change as the cause. You can’t attribute any singular weather event to climate change. It just doesn’t work that way.
Certainly, some computer models suggest there will be an increase in hurricanes in the future due to climate change. In fact, many computer models anticipate an increase, in general, in extreme weather this century, though not necessarily hurricanes. But the jury’s out on whether such increases are already occurring.
Some studies conclude that they are, such as a paper published last year in Geophysical Research Letters. It ends with: “Thus our results suggest that predicted increases in Canadian forest fire occurrence due to anthropogenic climate change are already being observed.” A recent paper in the Journal of Climate concludes: “In the mid-latitudes, there is a widespread increase in the frequency of very heavy precipitation during the past 50 to 100 years.”
But other studies are inconclusive. Indeed, finding out if extreme weather events are actually increasing around the world, in either severity or frequency, is difficult due to a lack of good-quality data from areas outside major population centres. So, why would the author send out this red herring addressing a non-issue? One possibility is that he may have other motives. He has been quoted in the press stating: “This [global warming] is the biggest scientific hoax being perpetrated on humanity. There is no global warming due to human anthropogenic activities.”
Ah, so there you have it. Katrina and Rita, it seems, were just a convenient excuse to get the same tired “Global warming isn’t happening, and if it is, it has nothing to do with anything people are doing,” message out to the masses. The charitable among us might call that opportunistic. The cynical would call it ambulance chasing.
The world’s most prestigious scientific bodies – the US National Academy of Science, the Royal Society of the UK, the Royal Society of Canada, and others recently signed a declaration warning of “clear and increasing” climate change and urged our leaders to act. An analysis in Science of all 928 peer-reviewed climate studies published between 1993 and 2003 found that not a single one disagreed with the general scientific consensus on climate change.
To ignore such evidence and insist on “proof” flies in the face of the way science actually works. Science does not progress in a direct, linear path. There are no straight lines from discovery to discovery to enlightenment. When I tell university students today about some of the ideas we had about genetics when I was their age, they burst out laughing.
A recent analysis of scientific papers found that 50 percent of them are probably wrong. But that’s not entirely unexpected. We learn from our failures as much as from our successes. That’s the nature of the scientific process.
To demand absolute proof in science before acting on a threat is to ask the impossible. It’s not just anti-scientific; it’s anti-science.
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