Some of the climate change scientists worried that if we warmed up the world sufficiently, we'd melt the permafrost in places like alaska and sibera, which have been collecting methane for the past 11,000 years. The venting of this methane would then further accelerate the process of global warming.
Apparently this process started a few years ago.
I'm feeling pretty depressed and hopeless, its been nice having an environment, but we've triggered the avalanche and we're going to get crushed, At this point I feel like we're pretty much committed to large scale destruction for which there's little we can do to prevent it. (I feel like we're getting close to the choice between our extinction in the future or sacrifices now, we've already consigned vast numbers of other organisms to extinction..)