rationalskepticism.org

You don't read what's posted ..you apparently don't even follow the science as it unfolds. You fall back on your claimed superiority in reading graphs and accept the projections without question which you've been doing ad nauseum.

Thawing permafrost could wake ‘sleeping giant’ of more greenhouse gases, potentially derailing global climate goals.

That is from the UN
https://www.unenvironment.org/news-and- ... des-arctic

The sleeping giant is already awake.

30 APRIL 2019
Permafrost collapse is accelerating carbon release
The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.

and this from the tabloid Nature,
https://www.nature.com/articles/d41586-019-01313-4

This much is clear: the Arctic is warming fast, and frozen soils are starting to thaw, often for the first time in thousands of years. But how this happens is as murky as the mud that oozes from permafrost when ice melts.

As the temperature of the ground rises above freezing, microorganisms break down organic matter in the soil. Greenhouse gases — including carbon dioxide, methane and nitrous oxide — are released into the atmosphere, accelerating global warming. Soils in the permafrost region hold twice as much carbon as the atmosphere does — almost 1,600 billion tonnes1.

What fraction of that will decompose? Will it be released suddenly, or seep out slowly? We need to find out.

Current models of greenhouse-gas release and climate assume that permafrost thaws gradually from the surface downwards. Deeper layers of organic matter are exposed over decades or even centuries, and some models are beginning to track these slow changes.

But models are ignoring an even more troubling problem. Frozen soil doesn’t just lock up carbon — it physically holds the landscape together. Across the Arctic and Boreal regions, permafrost is collapsing suddenly as pockets of ice within it melt. Instead of a few centimetres of soil thawing each year, several metres of soil can become destabilized within days or weeks. The land can sink and be inundated by swelling lakes and wetlands.

Abrupt thawing of permafrost is dramatic to watch. Returning to field sites in Alaska, for example, we often find that lands that were forested a year ago are now covered with lakes2. Rivers that once ran clear are thick with sediment. Hillsides can liquefy, sometimes taking sensitive scientific equipment with them.

https://www.nature.com/articles/d41586-019-01313-4

Every week dozens of metal flasks arrive at NOAA’s Earth System Research Laboratory in Boulder, Colorado, each one loaded with air from a distant corner of the world. Research chemist Ed Dlugokencky and his colleagues in the Global Monitoring Division catalog the canisters and then use a series of high-precision tools—a gas chromatograph, a flame ionization detector, sophisticated software—to measure how much carbon dioxide, nitrous oxide, and methane each flask contains.

These air samples—collected at observatories in Hawaii, Alaska, American Samoa, and Antarctica, and from tall towers, small aircraft, and volunteers on every continent—have been coming to Boulder for more than four decades, as part of one of the world’s longest-running greenhouse gas monitoring programs. The air in the flasks shows that the concentration of methane in the atmosphere had been steadily rising since 1983, before leveling off around 2000. “And then, boom, look at how it changes here,” Dlugokencky says, pointing at a graph on his computer screen. “This is really an abrupt change in the global methane budget, starting around 2007.”

The amount of methane in the atmosphere has been increasing ever since. And nobody really knows why. What’s more, no one saw it coming. Methane levels have been climbing more steeply than climate experts anticipated, to a degree “so unexpected that it was not considered in pathway models preparatory to the Paris Agreement,” as Dlugokencky and several coauthors noted in a recently published paper.

https://www.wired.com/story/atmospheric ... knows-why/

and you sit content that the models are predictive .....all models are wrong...some are useful....just recall that.

Methane has an outsize effect on warming even tho the duration is far shorter than carbon it's certainly within the 20-30 year time frame.

It's going up faster than anticipated, it's not known why, it's not in your cherished condensed reports.

The physical evidence of methane release in the north and ocean verges is overwhelming and the measurements in the north are lacking.....do you really think we have the least notion of fires. methane release and permafrost melting across Siberia.?

The world community is making an admirable effort in working to curb AGW in some regions but we still have upwardly mobile emerging nations countering or even exceeding the mitigation efforts of the first world
....the effort to curb carbon emissions is woefully lacking in the kind of war footing that some want.

Processes beyond human control are in play as the planet nears 1.5C above pre-industrial, that rise is not uniform and strongly magnified in the north where in the UN's own words "sleeping giant" risk lies.

The IPCC reports themselves are not the underlying science ...often the risks are downplayed.

There is a consistent pattern in the IPCC of presenting detailed, quantified (numerical) complex-modelling results, but then briefly noting more severe possibilities—such as feedbacks that the models do not account for—in a descriptive, non-quantified form. Sea levels, polar ice sheets and some carbon-cycle feedbacks are three examples. Because policymakers and the media are often drawn to headline numbers, this approach results in less attention being given to the most devastating, high-end, non-linear and difficult-to-quantify outcomes.

Twelve years ago, Oppenheimer and co-authors pointed out that consensus around numerical results can result in an understatement of the risks:

The emphasis on consensus in IPCC reports has put the spotlight on expected outcomes, which then become anchored via numerical estimates in the minds of policymakers…it is now equally important that policymakers understand the more extreme possibilities that consensus may exclude or downplay…given the anchoring that inevitably occurs around numerical values, the basis for quantitative uncertainty estimates provided must be broadened.

http://www.climatecodered.org/2019/04/e ... -un_8.html

There is hardly the need for polemics ....it's there in the science ...muted in the consensus.