According to some environmentalists and scientists, climate change was knocking down Washington’s door—and its power lines—this past weekend.
About 4.3 million people throughout the Midwest and Mid-Atlantic lost power over the weekend in the wake of a series of unusually severe and long-lasting thunderstorms—known as a “super derecho”—that hit the region on Friday night in part because of the region’s record-high temperatures.
“I think climate change is contributing to the severity of these storms because it’s adding energy to the climate system,” said Dan Lashof, director of the Natural Resources Defense Council’s climate and clean air program. “We are clearly seeing a trend toward more extreme precipitation events, more severe storms of this kind.”
The relentless heat wave hitting much of the country, the violent thunderstorms that heat wave in part caused on Friday, and the droughts and raging wildfires in Colorado and elsewhere have thrust to the forefront a cyclical debate about cause and effect: Is a warming Earth, caused by human activity, causing these extreme-weather events?
Climate and weather scientists are cautious about drawing a direct line from A to B, but most agree that a warmer planet will cause a higher frequency of extreme-weather events—even if you can’t scientifically prove that one single extreme-weather event is caused by climate change. It’s a subtle distinction and one that’s lost in Washington politics, where the debate boils down to black and white.
“It’s a treacherous issue,” said Kerry Emanuel, a climate-change scientist and an atmospheric science professor at the Massachusetts Institute of Technology. “When considering extreme weather and climate, you have to be mindful. It’s easy to step on a political or scientific mine and have it go off in your face.”
Greg Carbin, warning-coordination meteorologist for the National Oceanic and Atmospheric Administration’s Storm Prediction Center, said he didn’t “want to be specific about any one event.” But, referring to the wildfires, heatwaves, and thunderstorms, he added: “The science seems to suggest that in a warmer world, we will see more of these events.”
Politicians, meanwhile, jump into the minefields of climate change and extreme weather. Rep. Edward Markey, D-Mass., who chaired the House Select Committee on Global Warming in the last Congress, blasted Republican presidential nominee Mitt Romney for his recent equivocation on climate-change science.
“Hundreds of millions of American citizens have been afflicted by extreme weather events in the last two years, from wildfires to heatwaves to floods,” Markey said in a statement on Monday. “Mitt Romney is attempting to become the president for all of America’s citizens, yet he has no interest in protecting them from these events that have been supercharged by climate change.”
A spokesman for Senate Environment and Public Works ranking member James Inhofe, R-Okla., who does not think anthropogenic climate change is occurring, blasted Markey for his comments.
“It was only a matter of time before someone came out and wanted, for political gain, to link global warming to recent events,” said Inhofe spokesman Matt Dempsey. “These scare tactics have always backfired, and they will this time.”
MIT's Emanuel says that the most undeniable evidence that climate change is occurring—and that human activity is a big factor—is the unequivocal rise in global temperature in recent years. But that’s not what grabs people’s attention.
"Climate change will affect human beings principally through its effect on weather extremes. We are more affected by increasing incidence of floods, droughts, and heatwaves than we are by small changes in the average temperature," Emanuel said. "It's an important topic, but you have to be very careful when looking for signatures of it."
Washington should brace for more extremes—the temperature is forecast to near the century mark almost every day this week.