A recent paper in Nature Geoscience has shown that human caused warming could pump enough methane out of the Arctic tundra to raise the Earth’s temperature by between .4 and 1.5 degrees Fahrenheit. The paper, entitled Significant contribution to climate warming from the permafrost carbon feedback, showed that between 6 and 44 percent of all permafrost carbon could be emitted by 2100.
Since there’s more carbon in the permafrost than what has been historically emitted via fossil fuels, this number is large and very significant. The result of such an emission, even on the lower end, would be a significant contribution from nature to an already difficult to deal with man-made warming.
Research indicated that carbon emissions would be equal to between 40 and 100 additional parts per million CO2. However, a substantial portion of this increase would, initially, be methane, which, as a greenhouse gas, is 25 to 70 times stronger than CO2. This would seem to indicate that the researchers’ initial estimates of warming potential from permafrost carbon emission is low. And the researchers, themselves, admit their first estimates are conservative.
Perhaps, the most ominous outlook in the study is that it found that the amount of greenhouse gases to be emitted from permafrost over the next century largely cancel out carbon absorption by the oceans. Furthermore, the study did not take into account carbon emissions coming from methane hydrates in the ocean or from carbon sources in Antarctica once significant areas of that continent begin to thaw.
What this means is that, even were CO2 emissions to cease this decade, CO2 levels will likely remain above 400 ppm for as much as three hundred years. And this extended duration of high CO2 has substantial repercussions when it comes to the future shape of the world’s ice sheets and future ocean levels.
What this also means is that we are essentially locked in to melting Greenland and West Antarctica and to an additional 2-3 degrees Celsius warming now. Continued emissions via fossil fuels make the problem of global warming even worse. Andrew Skuce, in a recent response to this paper published in Skeptical Science noted:
“Unfortunately, there are several good reasons to consider the outlook in this study as rosy — as the authors themselves make clear. However, as bad and inevitable as they are, feedbacks from the permafrost are just the (de-)frosting on the fossil fuel cake that we are busy baking. It is still up to us to influence how severe climate change is going to be.”
Skuce is somewhat euphemistic and unclear in his assessment. I will not mince words. We are on track to a hotter world if we stop fossil fuel emissions now. Things are even hotter if we cut back fuel emissions soon. Continued fossil fuel emissions, without reductions, however, puts us on a short path to 1000 ppm CO2 by the end of this century. And that path is a short, hot road to hell.