beyond the quote, climate change edition

Bjørn Lomborg takes environmentalists to task for “pitching beyond the facts” in order to get people to take global warming seriously:

Remember how, in the wake of Hurricane Katrina in 2005, Al Gore (and many others) claimed that we were in store for ever more devastating hurricanes? Since then, hurricane incidence has dropped off the charts; indeed, by one measure, global accumulated cyclone energy has decreased to its lowest levels since the late 1970’s. Exaggerated claims merely fuel public distrust and disengagement.

I don’t disagree with that last sentence. It probably behooves all of us non-scientists to be careful about our claims that this or that weather pattern is “what the future looks like” thanks to global warming, WHY WON’T ALL YOU PRICKS BUY A PRIUS ALREADY???

But when Lomborg gets specific with his refutations, it looks to me like he’s playing fast and loose with the science himself. He disputes two specific claims — Paul Krugman’s assertion that this summer’s drought is a sign of global warming, and Bill McKibben’s warning that wildfires are going to be much more likely and severe in the future. Here are the relevant paragraphs on American droughts:

Consider Paul Krugman, writing breathlessly in the New York Times about the “rising incidence of extreme events” and how “large-scale damage from climate change is … happening now.” He claims that global warming caused the current drought in America’s Midwest, and that supposedly record-high corn prices could cause a global food crisis.

But the United Nations climate panel’s latest assessment tells us precisely the opposite: For “North America, there is medium confidence that there has been an overall slight tendency toward less dryness (wetting trend with more soil moisture and runoff).”

The quote from the IPCC report is not inaccurate, but the same paragraph also notes that “analyses for some subregions also indicate tendencies toward increasing dryness.” More importantly, “The most severe droughts in the 20th century have occurred in the 1930s and 1950s, where the 1930s Dust Bowl was most intense and the 1950s drought most persistent in the United States….” And, according to table 3.2, “regional variability and 1930s drought dominate the signal” — meaning, in plainer language, that it’s been getting wetter in some places but drier in others (this is also true even within the subregions), and that a significant portion of the gains in wetness are simply the result of us shaking off the last great man-made natural disaster.

This doesn’t mean Lomborg is wrong, exactly, but the IPCC’s total picture is more complicated that he’s letting on.

Let’s call that one a wash. But here’s Lomborg on wildfires:

Bill McKibben similarly frets in The Guardian and The Daily Beast about the Midwest drought and corn prices. Moreover, he confidently tells us that raging wildfires from New Mexico and Colorado to Siberia are “exactly” what the early stages of global warming look like.

In fact, the latest overview of global wildfire incidence suggests that, because humans have suppressed fire and decreased vegetation density, fire intensity has declined over the past 70 years and is now close to its preindustrial level.

Here’s the article he links to. Lomborg’s suggestion that it somehow discredits McKibben’s thesis is simply wrong-headed. Compare McKibben…

The record-setting temperatures (it had never been warmer in Colorado) that fueled those blazes drifted east across the continent as the week wore on: across the Plains, there were places where the mercury reached levels it hadn’t touched even in the Dust Bowl years, America’s previous all-time highs….

If we play politics for a generation, then weeks like the one we’ve just come through will be normal, and all we’ll be doing as a nation is responding to emergencies.

… with the abstract of the paper, which I think Lomborg has to bend over backwards to read as good news:

We find that during the preindustrial period, the global fire regime was strongly driven by precipitation (rather than temperature), shifting to an anthropogenic-driven regime with the Industrial Revolution. Our future projections indicate an impending shift to a temperature-driven global fire regime in the 21st century, creating an unprecedentedly fire-prone environment. These results suggest a possibility that in the future climate will play a considerably stronger role in driving global fire trends, outweighing direct human influence on fire (both ignition and suppression), a reversal from the situation during the last two centuries.

How is that different, exactly, from what McKibben’s saying? I mean, it’s great that campfires aren’t causing so many fires these days, but what about the UNPRECEDENTEDLY FIRE-PRONE ENVIRONMENT caused by climate change? Can we maybe look into that?

Yes, we should be careful not to overinflate what we know. No, one droughty summer does not mean America is in for a century of food crises, and one big fire in Colorado doesn’t signal a future of perpetual unsolicited outdoor barbecue in the West. But maybe we also shouldn’t go around needlessly undermining people who are sounding the alarm — especially when the science doesn’t contradict them.

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One Response to beyond the quote, climate change edition

  1. Pingback: more evidence that Bjørn Lomborg is wrong | The Handsome Camel

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