Starting in 2010, arctic methane emissions from subsea methane hydrates exploded, as noted by the study cited in this blog. Their conclusion?
Developed (and some developing) countries must cut back their carbon dioxide emissions by a very large percentage (50% to 90%) by 2020 to immediately precipitate a cooling of the Earth and its crust. If this is not done the earthquake frequency and methane emissions in the Arctic will continue to grow exponentially leading to our inexorable demise between 2031 to 2051.Though I'm no expert on atmospheric methane, this is disturbing to say the least, and likely explains the wild jump in temperatures we experienced over much of the northern hemisphere last winter, this summer, and in what is materializing this winter as well. Going agrarian, or rewilding isn't really an option when the planet no longer supports human life, as now appears to be likely within a matter of a couple decades.
The methane concentrations being cited are likely to lead to a "Permian Extinction" type event by mid-century, occuring first within the northern hemisphere.
Meanwhile, here in the Michigan, people are up in arms over a recent failed state initiative to require a 25% renewables mix in our electricity generation by 2025. In light of this information, that goal sounds laughable. We shouldn't be focusing on how much renewable energy we're generating, because much of it is not zero-carbon once the infrastructure and maintenance is figured in. We should simply focus on reducing our fossil fuel use. A 90% reduction in carbon emissions is likely far too conservative.