The author and climate campaigner Bill McKibben, fresh from protests over the proposed Keystone XL pipeline, wrote today, “Irene’s got a middle name — and it’s global warming.”
McKibben and his source for data on the storm, Wunderground meteorologistI Jeff Masters, are right when they say this storm is being fed by extremely warm sea temperatures and will be producing extraordinary rainfall (as I wrote on Wednesday). [Hurricane updates are here.]
But McKibben’s effort to use this United States hurricane landfall as a specter of things to come in a greenhouse-heated world doesn’t mesh with the science, which shows a measurable, though subtle, trend in the opposite direction. That’s why I agree with Keith Kloor’s conclusion that this kind of rhetoric is “undermining the legitimacy” of the call to reduce emissions of greenhouse gases.
In 2008, researchers from the National Oceanic and Atmospheric Administration and University of Miami published “Global warming and United States landfalling hurricanes,” a long-view analysis of patterns in hurricanes striking United States shores in relation to climate conditions. Their prime conclusion was that warming seas are associated with rising wind shear — a hurricane-killing condition — in the part of the Atlantic that is a nursery for the kinds of hurricanes that tend to strike the United States. The rise in wind shear appears to be associated with “a weak but robust downward trend in U.S. landfalling hurricanes.” Their work built on earlier analysis drawing the same conclusion.
Here’s their graph of the storm-strike trend:
Earlier today, I contacted the lead author, Chunzai Wang, an oceanographer at the federal Atlantic Oceanographic and Meteorological Laboratory, and he said that subsequent hurricane patterns have bolstered their findings:
I can assure you that the conclusion is still held (even much firmer) if we use the updated hurricane data. Keep in mind that the 2010 Atlantic hurricane season had 12 hurricanes, but not a single hurricane made landfall in the United States.
The kind of framing used by McKibben in the Daily Beast also came up during the astounding tornado outbreaks earlier this year, as Michael Mann of Pennsylvania State University told ThinkProgress that “climate change is present in every single meteorological event.”
This is as uncontroversial as saying the sky is blue, in the sense that the atmosphere’s behavior is implicitly shaped differently than it was before the industrial revolution raised the concentration of carbon dioxide by more than a third. The beautiful conditions I see out my window in the Hudson Valley ahead of the storm are shaped by that reality as well.
But the important question for society is how much climate events that matter to people are being meaningfully shaped by that rise in greenhouse gases. In the case of American hurricane risk, the science says there’s a negative trend in storm number, while storm energy and rainfall probably are rising.
So is Irene’s middle name “global warming”?
I say its middle name is “stay out of my way.”