During an unusually hot summer this year, researchers in Siberia stumbled upon fifteen of these oddly bouncy patches of grass. They suspected, according to the Siberian Times, methane bubbling up from melting permafrost---and subsequent stories were quick to connect it to climate change. But permafrost experts say it’s more likely a pool of water than a methane bubble.
“I’ve seen this before,” said Kevin Schaefer when I asked him to watch the video. “It’s a mat of vegetation sitting on top of water.” Schaefer, who is a permafrost researcher at the US National Snow and Ice Research Center, said he’s encountered patches of ground just like this up in Barrow, Alaska. “We were doing some surveying and all of a sudden we were bouncing like on a water bed.”
In fact, these pools of water exist because of unique ground conditions in the Arctic. During the summer, the top layers of the ground melt, but the frozen permafrost underneath remains, well, permanent and impenetrable. “It acts like a bucket and fills up with water. It’s generally very wet,” says Schaefer. Pools of water might build up under what looks like solid ground. “It’s common,” says Vladimir Romanovsky, a geophysicist at University of Alaska Fairbanks.
The photos published in the Siberian Times do show water seeping out of the ground after researchers punctured it. The team also found high levels of carbon dioxide and methane gas, which is in fact exactly what you’d expect. When the ground melts in Siberia, the dead grass and other organic matter in the ground begins to decay. Microbes that eat this stuff turn it into carbon dioxide (if oxygen is present) or methane (if no oxygen is present, as when covered in water).
Now Siberia, methane, and climate change have been in the news before---thanks to dramatic photos showing new craters suddenly appearing in the tundra. In that case, researchers now suspect warming temperatures had melted enough ice to allow big pockets of methane to escape. These pockets of methane, though, came from microbes that lived millions of years ago, stored in permafrost until now. The smaller amounts of methane from the water pools came from recent microbes. This phenomenon is smaller in scale, both geologically and chronologically.
Climate change may still play a role. “If it’s unusual for that particular place,” says Romanovsky, “it is an indication that the summer thaw is deeper.” And that would be worrying because permafrost locks up a lot of carbon. If the Earth gets warm enough from fossil fuel emissions, it’ll start melting permafrost, which ordinarily preserves dead matter like a giant refrigerator. Once microbes get to the unfrozen dead matter, they emit carbon dioxide and methane, making climate change even more severe. It’s a runaway effect.
If you, like me, felt concerned about this man stomping all over a seething bubble of methane, you can rest easy knowing it’s probably just water. If you felt concerned about climate change, please do continue to worry.
