The terrible and terrifying news of impending climate-change doom continues to roll in. This week it was a study led by researchers at Britain’s University of East Anglia: “Climate Change and Future Pollen Allergy in Europe.” The scientists project that, because of rising temperatures and increased carbon dioxide in the atmosphere, “sensitization to ragweed will more than double in Europe, from 33 to 77 million people, by 2041-2060.” So go ahead and add allergy sufferers to polar bears and small island nations on the list of global warming victims.
The eagle-eyed will already have noticed that something is amiss: The number of likely snifflers is quite precise—77 million—but the timetable for achieving that specific number is laughably imprecise, a range of 20 years. The Scrapbook is quite certain that the good professors crunched the numbers correctly, but if you’re predicting something will happen sometime in a 20-year window—and a window that opens a quarter of a century from now, at that—perhaps a little rounding would be in order. But, of course, such scientific modesty would undermine the impression of certainty that comes from specificity, however bogus that specificity may be. (Give them this much: At least they didn’t say there would be 76,895,352 sufferers.)
The authors of the study, published in Environmental Health Perspectives, make quite grand claims for their work. “Globally pollen allergy is a major public health problem, but a fundamental unknown is the likely impact of climate change,” the report begins. “To our knowledge, this is the first study to quantify the consequences of climate change upon pollen allergy in humans.” Perhaps, but they are hardly the first (or even second, third, or fourth) to warn of the looming weed-pollen apocalypse. The U.S. Environmental Protection Agency, for example, devotes a whole page of its 2016 Climate Change Indicators to the change in ragweed pollen season over the last decade. It is by now well-established that weeds, under the influence of global warming, will grow like weeds.
And not just pollinating weeds. Watch out for poison ivy, too. For a decade, scientists have been warning that climate change will mean a more menacing three-leaved menace—bigger plants, with bigger leaves, and perhaps even with higher concentrations of poisonous oil.
But why all the negativity? If ragweed is spreading, it isn’t because climate change is creating conditions that exclusively benefit weeds. An atmosphere rich in carbon dioxide can have a “fertilizer effect.” Warmer temperatures can extend the growing season in cool climes. These are assumptions that are built into studies such as the new ragweed report. It’s also what goes into the poison ivy predictions—grow the stuff in greenhouse conditions and (surprise, surprise) it flourishes. Those same effects, however, will benefit a wide range of plants. Longer growing seasons and higher levels of atmospheric carbon dioxide have benefited Canadian farmers, who have been able to dramatically expand the acreage they devote to growing corn, soybeans, and other crops that used to flourish only south of the border.
To the extent temperatures change—whether that change is naturally occurring or man-made—there are going to be winners and losers, damaging consequences and beneficial ones. Cool climates may benefit from a little less chill; warm regions may suffer. Yes, in the northern parts of Europe and North America, weeds may expand their range, grow bigger, and give off more pollen. But so, too, will desirable plants enjoy the more-verdant conditions. Why is it that all we hear about are the downside consequences? Perhaps the negatives of climate change will outweigh or overwhelm the positives. But as things stand, we don’t hear about the positives; they never seem to enter into the equation.
We are constantly being told that when it comes to questions of climate we must obey Science. Could it be that scientists would enjoy greater credibility if they made a better effort to give a complete picture of the consequences of a warming world, rather than just nurturing the negatives in their own little intellectual hothouses?
