One of the most worrying positive feedbacks of our current climate change lies deep in the Arctic permafrost and the ocean – methane hydrates. Methane loosely bonds to water, which freezes and lies stable…..until it melts. When it gets warm enough, the methane breaks apart from the water and is released into the atmosphere, or is dissolved in the ocean and then slowly released.
There is an enormous amount of methane in the form of hydrates up north – using its GWP, enough to “double” the amount of CO2 (even if it doesn’t all convert to CO2), if I remember correctly. This feedback is not included in climate models, as nobody really knows when or at what point huge amounts of methane could be released.
Unfortunately, we have evidence that it’s starting to begin. CORDIS and BBC report that a study in Geophysical Research Letters has discovered methane plumes rising from the ocean floor. Right now the methane is dissolving in the water, but we don’t know whether or when it’ll reach the atmosphere. Even if the methane stays dissolved, the acidity of the ocean will increase, which can damage marine life. Even if this begins as only an impact, not a feedback, the Arctic is stressed out enough as it is.
I didn’t expect to hear news like this for quite a few years. As one of the authors says, “Our survey was designed to work out how much methane might be released by future ocean warming; we did not expect to discover such strong evidence that this process has already started.”
Reminds you a bit of Larsen-B, doesn’t it?