Bad methane news

As Arctic Ocean warms, megatonnes of methane bubble up - Environment - New Scientist

Over 250 plumes of gas have been discovered bubbling up from the sea floor to the west of the Svalbard archipelago, which lies north of Norway. The bubbles are mostly methane, which is a greenhouse gas much more powerful than carbon dioxide.

Interestingly, though, the methane in this particular area is not making to the top of the ocean. Instead, it dissolves and partly contributes to ocean acidification:

None of the plumes the team saw reached the surface, so the methane was not escaping into the atmosphere and thus contributing to climate change – not in that area, at least. "Bigger bubbles of methane make it all the way to the top, but smaller ones dissolve," says Minshull.

Just because it fails to reach the surface doesn't mean the methane is harmless, though, as some of it gets converted to carbon dioxide. The CO₂ then dissolves in seawater and makes the oceans more acidic.

And it is possible that other, more vigorous plumes are releasing methane into the atmosphere. The team studied only one group of plumes, which were in a small area and were erratic.

"Almost none of the Arctic has been surveyed in a way that might detect a gas release like this," Minshull says.

I wonder, though, whether this is something that might have been going on before the waters increased in temperature by 1 degree. Maybe just no one was looking before.