Last week I wrote about a study that said something unusual—climate change may not turn out to be as serious as our worst fears. Well, there was a reason why that study was such an outlier—most of the science on climate change is dire and getting direr.
Case in point: a new article in this week’s Nature that explores what global warming might do to the methane gas buried beneath the permafrost. Methane has 23 times the global warming power of carbon dioxide, and there are billions of tons worth of it trapped in the Arctic. As the climate warms, some of that permafrost will become less permanent, melting and allowing the methane to escape and add to global warming—which will in turn speed climate change. That’s why Arctic methane has always been considered a climate “wildcard”—how fast it escapes from the tundra could have major impacts on the rate of warming.
Well, that wildcard is threatening to bust our hand, or some similar blackjack metaphor. According to the authors of the Nature article, Arctic warming of 7.5 C this century could allow the equivalent of 380 billion tons of carbon dioxide to escape as soils thaw. That would provide a major boost to warming.
As the authors write:
We calculate that permafrost thaw will release the same order of magnitude of carbon as deforestation if current rates of deforestation continue. Because these emissions include significant quantities of methane, the overall effect on climate could be 2.5 times larger.
Just so you can visualize it, here’s film of scientist Katey Walker igniting leaking methane from a frozen lake:
So for all the attention rightfully paid to stopping deforestation, allowing methane to leak from the permafrost could be even worse. 7.5 C is a lot of warming, though it’s important to note that climate change is happening faster in the far north than it is in the rest of the world. But even with 2 C of warming—which increasingly seems to be an unrealistic target, given global energy use—huge amounts of methane would still escape the soil and heat the atmosphere.
Scary stuff. But at least things are back to normal on the climate science beat: vaguely apocalyptic.