Arctic Sea Ice : Forum

AGW in general => Science => Topic started by: wili on May 02, 2014, 07:45:47 PM

Title: Study on Permafrost Melt: Arctic Methane Emissions ‘Certain to Trigger Warming'
Post by: wili on May 02, 2014, 07:45:47 PM
http://www.climatecentral.org/news/arctic-methane-emissions-certain-to-trigger-warming-17374 (http://www.climatecentral.org/news/arctic-methane-emissions-certain-to-trigger-warming-17374)

Quote
As climate change melts Arctic permafrost and releases large amounts of methane into the atmosphere, it is creating a feedback loop that is "certain to trigger additional warming," according to the lead scientist of a new study investigating Arctic methane emissions.

The study released this week examined 71 wetlands across the globe and found that melting permafrost is creating wetlands known as fens, which are unexpectedly emitting large quantities of methane. Over a 100-year timeframe, methane is about 35 times as potent as a climate change-driving greenhouse gas than carbon dioxide, and over 20 years, it's 84 times more potent.
(Schindel et al. 2006 puts that last figure at 105.)

Quote
...a spike in global methane concentrations in the atmosphere seen since 2007 can be traced back to the formation of fens in areas where permafrost once existed...

“Methane emissions are one example of a positive feedback between ecosystems and the climate system,” Turetsky said. “The permafrost carbon feedback is one of the important and likely consequences of climate change, and it is certain to trigger additional warming.”

“Even if we ceased all human emissions, permafrost would continue to thaw and release carbon into the atmosphere,” Turetsky said. “Instead of reducing emissions, we currently are on track with the most dire scenario considered by the IPCC. There is no way to capture emissions from thawing permafrost as this carbon is released from soils across large regions of land in very remote spaces.”

..."It's not to say at some point it won't become an issue," Schmidt said, adding that there is evidence of many "methane burps" across the globe in the very distant past.

"The planet is very capable of surprising us," he said.
Title: Re: Study on Permafrost Melt: Arctic Methane Emissions ‘Certain to Trigger Warming'
Post by: Steven on May 03, 2014, 01:53:19 PM
Thanks, wili.  One of your quotes was slightly changed by the Climate Central journalist:

Quote
...a spike in global methane concentrations in the atmosphere seen since 2007 can be partly traced back to the formation of fens in areas where permafrost once existed...

(He added the word "partly").  The original news release from University of Guelph is here (http://www.uoguelph.ca/news/2014/04/wetlands_likely.html).

The increase since 2007 is also partly attributed to tropical wetlands, industrial gas leaks, etc.  Here's a nice 1-page summary paper by Nisbet et al. 2014:

Methane on the Rise - Again (http://www.ingos-infrastructure.eu/?wpfb_dl=247)

with the following image of methane growth rate by latitude:

(https://www.sciencemag.org/content/343/6170/493/F2.large.jpg)
Title: Re: Study on Permafrost Melt: Arctic Methane Emissions ‘Certain to Trigger Warming'
Post by: TerryM on May 03, 2014, 03:48:28 PM
The change post 2006 at all latitudes was unexpected (by me). I had no idea that the SH had undergone such a huge transformation.


Terry
Title: Re: Study on Permafrost Melt: Arctic Methane Emissions ‘Certain to Trigger Warming'
Post by: crandles on May 03, 2014, 04:04:19 PM
The change post 2006 at all latitudes was unexpected (by me). I had no idea that the SH had undergone such a huge transformation.


Terry

There was Distinct level patch 1999-2006 that seems unusual but then takes off again:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fgmd%2Fwebdata%2Fiadv%2Fccgg%2Fgraphs%2Fccgg.MLO.ch4.1.none.discrete.all.png&hash=7c3c803dcd1490538f90dd56e30fdba4)