Scientists say that the powerful greenhouse gas methane is escaping from the sea bed off Norway as the ice it is trapped in melts.
Warming of the oceans by anthropogenic means results in the release of methane. Methane increases the effects of greenhouse gases, producing a positive feedback loop that can not be easily broken. This is a large tipping point, which could put us into a new climate regime no matter what we do.
This is more than just heating the atmosphere. Methane dissolved in water become carbon dioxide, reducing the ability of the oceans to act as a carbon dioxide sink and remove the gas from the atmosphere. In addition, the increase in dissolved carbon dioxide makes the oceans more acidic, and making it much more difficult for the plankton that are necessary a for almost all ocean life to survive.
Many scientists did not think that this much methane would be released until later in the century, giving us more time to fix our carbon release procedures. Now, it may well be that the best we can hope for is to ameliorate the effects. Reversing them may have become much more difficult.
Very depressing news. We need to not only begin figuring out ways to isolate large amounts of carbon dioxide from the air and segregate it but also from the ocean.