Checking Senator Murkowski’s Volcano Math

Incoming Chair of the Senate Natural Resources Committee Lisa Murkowski acknowledged on election night that her state is feeling the effects of a warming planet. But then she said something curious. According to NPR, when asked about whether humans are causing climate change, the Senator “mentioned a volcano she had heard about in Iceland. ‘The emissions that are being put in the air by that volcano are a thousand years’ worth of emissions that would come from all of the vehicles, all of the manufacturing in Europe,’ she said.” NPR, to its credit, included a terse rebuttal from Princeton professor Michael Oppenheimer: “It’s simply untrue. I don’t know where she gets that number from.” That got me curious about where, indeed, she might have gotten the number from, and what the actual math looks like.

I took to the Googles, and this is the only thing I found that seemed like it might have been the source, due to the specific comparison to Europe:

“The sulfur dioxide (SO2) emitted from the Holuhraun eruption has reached up to 60,000 tons per day and averaged close to 20,000 tons since it began,” notes Pall Stefanson, in a September 25 report for Iceland Review Online. “For comparison, all the SO2 pollution in Europe, from industries, energy production, traffic and house heating, etc., amounts to 14,000 tons per day.”

If this is Senator Murkowski’s source for the comparison between the “emissions” from the Icelandic volcano, and all the “emissions” in Europe, there are a couple of glaring problems. First of all we are talking about a completely different pollutant. SO2 is some nasty stuff, but it’s not a major greenhouse gas the way CO2 is. In fact, as an aerosol in the atmosphere it actually has a slight shading and cooling effect—opposite of what CO2 does. It has also been the target of extensive, successful reduction efforts over many decades (also unlike CO2). The other problem, of course, is that there is no way to get to 1000 years’ worth of emissions when you are talking about a volcano with an output of 2-4 times that of Europe, that has so far erupted for about 1/6th of a year.

So how much CO2 is coming out of that Holuhraun volcano? According to the University of Iceland, about half as much CO2 as SO2 is being emitted, so a ballpark figure would be 30,000 tons per day. That sounds like a lot. But here’s the thing: according to the most recent estimate, worldwide fossil fuel emissions are about 30 Gigatons per year. “Gigatons” means billions of tons. Here’s what that looks like written out: 30,000,000,000. Divided by 365, the world’s fossil fuels emit 82,192,000 tons of CO2 per day. (By the way, that’s not counting other sources, like deforestation or other GHGs, when those are added the world’s GHG emissions are closer to 50 GT/year). In short, each day’s eruption of the “Icelandic volcano” is putting out roughly 0.04 percent of the CO2 put out by fossil fuel burning. In fact, Senator Murkowski has it exactly backwards: Holuhraun could erupt at its current pace for 1,000 years, and it still wouldn’t produce the amount of CO2 that humans emit in one year.

Aimee Delach is a Senior Policy Analyst at Defenders of Wildlife