Guest slam dunk by David Middleton
From the “I couldn’t make this sort of schist up, if I was trying files”…
Scientists feared unstoppable emissions from melting permafrost. They may have already started.
The Arctic is a ticking time bomb that’s close to going off.
By Brian Resnick@B_resnickbrian@vox.com Dec 12, 2019
Every year, the National Oceanic and Atmospheric Administration releases an Arctic Report Card, detailing the state of the frozen world at the top of the globe.
And each year, its findings grow more dire. This year, the report revealed that the Arctic itself may now be contributing to climate change. That’s because Arctic soil contains a lot of carbon, which would stay there if it weren’t for the fact that the planet is warming. As the frozen ground across the Arctic starts to thaw, it releases that carbon, which turns into a greenhouse gas. Some of that carbon gets taken up by plants growing in the summertime, but more and more of it is now escaping into the atmosphere.
“Thawing permafrost throughout the Arctic could be releasing an estimated 300-600 million tons of net carbon per year to the atmosphere,” the NOAA writes in the report. That’s roughly the equivalent of Japan’s annual emissions.
And those emissions are going to increase. “We think that should be two to three times bigger by the end of the century based on the kind of forecasting we’ve done,” Ted Schuur, an ecologist and the author of the report’s section on permafrost, said.
And pigs may fly. The ecologist’s report was actually weaker than the Vox article.
A new comprehensive synthesis study of non-summer ecosystem CO2 fluxes across the circumpolar region showed that carbon release during the Arctic winter was 2 to 3 times higher than previously estimated from ground-based measurements (Fig. 3) (Natali et al. 2019). This circumpolar estimate suggests that carbon release in the cold season offsets net carbon uptake during the growing season (derived from models) such that the region as a whole could already be a source of 0.6 Pg C per year to the atmosphere. It was not possible to determine whether these higher flux estimates were a result of changing environmental conditions or the aggregation of more observations during this scarcely observed non-summer period. Regardless, similar to the regional extrapolation made by aircraft, this winter flux synthesis supports the idea that the accelerating feedback from changing permafrost ecosystems to climate change may already be underway.
SOP in fake science, “We have no previous baseline with which to determine if the new observations are anomalous… But we have models out the wazoo.”
However, they do have a 20-yr empirical experiment
News in Brief: Warming may not release Arctic carbon
Element could stay locked in soil, 20-year study suggests
By Erin Wayman
Web edition: May 15, 2013
Print edition: June 15, 2013; Vol.183 #12 (p. 13)
Researchers used greenhouses to artificially warm tundra (shown, in autumn) for 20 years. They found no net change in the amount of carbon stored in the soil.
The Arctic’s stockpile of carbon may be more secure than scientists thought. In a 20-year experiment that warmed patches of chilly ground, tundra soil kept its stored carbon, researchers report.
In the Alaska experiment, they warmed the permafrost by 2 °C over a 20-yr period (10 times the actual rate of warming since the 1800’s) and there wasn’t the slightest hint of an accelerated methane release.
And they have a schist load of paleoclimatology data
There is no evidence of widespread thawing of Arctic permafrost since Marine Isotope Stage 11 (MIS-11), approximately 450,000 years ago. None of the subsequent interglacial stages indicate widespread permafrost thawing, above 60°N, not even MIS-5 (Eemian/Sangamonian), which was about 2°C warmer than present day, possibly as much as 5 °C warmer in the Arctic.
Vaks et al., 2013 found no evidence of widespread permafrost thawing above 60°N since MIS-11, not even during MIS-5…
The absence of any observed speleothem growth since MIS 11 in the northerly Lenskaya Ledyanaya cave (despite dating outer edges of 7 speleothems), suggests the permanent presence of permafrost at this latitude since the end of MIS-11. Speleothem growth in this cave occurred in early MIS-11, ruling out the possibility that the unusual length of MIS-11 caused the permafrost thawing.
The degradation of permafrost at 60°N during MIS-11 allows an assessment of the warming required globally to cause such extensive change in the permafrost boundary.
Vaks et al., 2012
There is no evidence of widespread thawing of Arctic permafrost since Marine Isotope Stage 11 (MIS-11), approximately 450,000 years ago. None of the subsequent interglacial stages indicate widespread permafrost thawing, above 60°N, not even MIS-5 (Eemian/Sangamonian), which was about 2 °C warmer than present day, possibly as much as 5 °C warmer in the Arctic.
The last interglacial stage (MIS-5, Sangamonian/Eemian) was considerably warmer than the current interglacial and sea level was 3-6 meters higher than modern times. It was particularly warmer in the Arctic. Oxygen isotope ratios from the NGRIP ice core indicate that the Arctic was approximately 5 °C warmer at the peak of MIS-5 (~135,000 years ago).
It also appears that it was significantly warmer in the Arctic during the Holocene Climatic Optimum (~7,000 years ago) than modern times. The Arctic was routinely ice-free during summer for most of the Holocene up until about 1,000 years ago.
The best geological evidence for the Arctic methane time bomb being a dud can be found in the stratigraphy beneath Lake El’gygytgyn in northeastern Russia. The lake and its mini-basin occupy a 3.58 million year old meteor crater. Its sediments are ideally suited for a continuous high-resolution climate reconstruction from the Holocene all the way back to the mid-Pliocene. Unlike most other Arctic lakes, Lake El’gygytgyn, has never been buried by glacial stage continental ice sheets. Melles et al., 2012 utilized sediment cores from Lake El’gygytgyn to build a 2.8 million year climate reconstruction of northeastern Russia.
The data from Melles et al., 2012 are available from NOAA’s paleoclimatology library. And it is clearly obvious that Arctic summers were much warmer during MIS-11c (430-400 ka) than either the Eemian/Sangamonian (MIS-5e) or the Holocene (MIS-1)…
Even though there may have been widespread melting of Arctic permafrost during the early part of MIS-11c, there’s no evidence that it caused any sort of catastrophic rise in atmospheric greenhouse gases.
Figure 6. Atmospheric carbon dioxide, methane and nitrous oxide from Dome C in Antarctic (CDIAC).
Of course, there’s always the possibility that MIS-11c did experience a sub-resolution spike in greenhouse gases. Dome C can’t “see” short-duration spikes in atmospheric gases. We’re left with three possibilities:
- Much warmer temperatures and partial melting of permafrost during MIS-11c didn’t cause a spike in greenhouse gases.
- Much warmer temperatures and partial melting of permafrost during MIS-11c did cause a spike in greenhouse gases; but the Antarctic ice cores can’t resolve it.
- The unresolved spike in MIS-11c spike in atmospheric greenhouse gases caused the MIS-11c warming… but didn’t prevent the subsequent glacial stage cooling.
In other words…
Most of this post was previously published in these two posts of mine:
via Watts Up With That?
December 13, 2019 at 08:30PM