By David L. Brown
Well, things never seem to get better, do they? We have written here before about the effect that thawing permafrost in the Arctic could release large quantities of greenhouse gas (GHG), thus rapidly accelerating global warming. Now, according to a paper published in the scientific journal Nature Geoscience, things could be even worse than anyone thought.
The bad news is reported today on the Scientific American web site, here. According to the report,
“Drunken” trees listing wildly, cracked highways and sinkholes—all are visible signs of thawing Arctic permafrost. When this frozen soil warms, it releases carbon dioxide, methane and other greenhouse gases as microbes start to thrive on the organic material it contains—a potentially potent source of uncontrollable climate change.
Now new research published in Nature Geoscience shows that such frozen Arctic soil holds nearly twice as much of the organic material that gives rise to planet-warming greenhouse gases as previously estimated.
“When the air temperature rises two to three degrees, the Arctic tundra would switch from a carbon sink to a carbon source,” says soil scientist Chien-Lu Ping of the University of Alaska Fairbanks. “The greater the carbon stores, the greater the impact it causes,” including even faster warming in the already changing Arctic.
The on-going warming of the Arctic region could release most of the carbon that is presently sequestered in the frozen soil. The article quotes Ping, “Warming will increase the decomposition rate of the soil organic matter and more carbon dioxide will be generated.” He adds, “warming will thaw the permafrost and release the sequestered carbon,” which will also decompose faster in the warmer temperatures.
According to estimates, the permafrost contains an amount of GHG equal to one-sixth of the amount presently in the atmosphere. If that amount were to be released, it would boost the GHG load in the air by a significant amount, resulting in soaring global temperatures.
And lest you think that the Arctic is not thawing, read my August 20 post, “Despite Claims, Arctic Ice Meltdown Continues.” In fact, the graph I included there from the National Snow and Ice Data Center is updated regularly. Here is the latest chart:
As you can see, the amount of Arctic sea ice that is disappearing this season, as indicated by the solid blue line, continues to drop ominously. The loss in 2007 was significant and surprised even the specialists who follow this closely. The 2007 record loss is shown by the dotted line. As you can see, this year’s trend indicates that record loss could be equaled this year. We shall continue to monitor this important subject.