New scientific evidence supports that a climatic tipping point could be closer than we realize.
As the Arctic heats up at a rate twice that of the rest of the globe and as sea ice and glaciers turn to water, the permafrost is also thawing. A recent review article in the journal Nature found that as the unfrozen organic matter decays, vast stores of carbon in the permafrost could be released into the atmosphere. This will trigger an irreversible feedback system and nullify existing calculations of just how much carbon humans can burn and keep the globe within a relatively safe degree of warming.
The scientific understanding of the permafrost is new—so new, in fact, that it wasn’t ready in time for the latest round of climate assessment reports from the Intergovernmental Panel on Climate Change, the world’s largest scientific body on global warming.
The 2014 IPCC report estimated that to hold global warming below 2 degrees Celsius, worldwide carbon dioxide emissions would have to be cut by 40 percent to 70 percent by 2050, and then drop to nearly zero by the end of the century. This is a tall order on its own, and it does not take into account additional emissions from permafrost thawing.
— Sabrina Shankman, InsideClimate News