Peter, thank you for your post.
If you go to the web link provided in my post, there is a button for
providing 'feedback to the editors'.
The article itself provides this:
"More information: Torben Røjle Christensen et al, Tracing the climate
signal: mitigation of anthropogenic methane emissions can outweigh a
large Arctic natural emission increase, Scientific Reports (2019). DOI:
10.1038/s41598-018-37719-9"
That web link [https://www.nature.com/articles/s41598-018-37719-9] takes
you to the Nature journal website and the paper titled: "Tracing the
climate signal: mitigation of anthropogenic methane emissions can
outweigh a large Arctic natural emission increase"
The corresponding author for the original paper is Torben Røjle
Christensen, who can be contacted at
https://www.nature.com/articles/s41598-018-37719-9/email/correspondent/c1/new
(Frequently it takes a bit of effort to dig back through the chain to
find the original source.)
And of course, I invite you to provide your comment here.
I fully concur that offshore methane clathrates present an additional,
significant threat for increased methane emissions, which are 56 times
as potent as CO2 in terms of global warming potential (20 year impact).
[https://unfccc.int/process/transparency-and-reporting/greenhouse-gas-data/greenhouse-gas-data-unfccc/global-warming-potentials},
and we have to stop talking about longer timeframes - climate change is
not giving us more time.
[https://climateanalytics.org/briefings/why-using-20-year-global-warming-potentials-gwps-for-emission-targets-is-a-very-bad-idea-for-climate-policy/]
Darryl McMahon
On 2/9/2019 5:14 AM, Peter Wadhams wrote:
Dear Darryl,
Thanks for letting me join this list. Is there a proper place for sending comments on pieces?
If so, I'd like to insert a comment on the paper that is referred to, which is that it only deals with
methane from melting terrestial permafrost, and does not even mention the much bigger and more immediate threat, which is offshore methane from
the sediments on Arctic continental shelves (East Siberian, Kara, Laptev Seas). That is the elephant in the room,
mentioned by many scientists (e.g. in my book "A Farewell to Ice", Oxford UnivPress), but carefully ignored by IPCC.
Best wishes
Peter Wadhams
On Sat, Feb 9, 2019 at 2:29 AM Darryl McMahon <darryl@xxxxxxxxxxxxx <mailto:darryl@xxxxxxxxxxxxx>> wrote:
https://phys.org/news/2019-02-diffusing-methane-bombwe-difference.html
[links in online article]
Defusing the methane bomb—we can still make a difference
February 7, 2019, International Institute for Applied Systems Analysis
The Arctic is warming twice as fast as the rest of the planet, causing
the carbon-containing permafrost that has been frozen for tens or
hundreds of thousands of years to thaw and release methane into the
atmosphere, thereby contributing to global warming. The findings of a
study that included researchers from IIASA, however, suggest that it is
still possible to neutralize this threat.
Permafrost is soil that remains frozen for two or more consecutive
years. It is usually composed of rock, soil, sediments, and varying
amounts of ice that bind the elements together. The permafrost of the
Arctic landscape represents one of the largest natural reservoirs of
organic carbon in the world. When the permafrost thaws, the soil
microbes contained in the soil can turn the carbon into carbon dioxide
and methane, which are both greenhouse gases that are known to
contribute to global warming when released into the atmosphere.
Unfortunately, this is exactly what is currently happening as a result
of climate change. In fact, the massive amounts of methane that could
potentially be released as a result of permafrost thaw, has often been
described as a ticking time bomb and has long been a concern for
climate
scientists.
A study by researchers from IIASA, Canada, Denmark, Norway, and Sweden,
however, suggests that it is possible to neutralize the natural gas
threat that lies in wait under the Arctic soil. The team looked at
several possible future scenarios, including some where the world
continues to release manmade carbon and methane emissions into the
atmosphere at the current rate, and some where we meet the targets of
the Paris Agreement.
In their analysis, the researchers quantified the upper range value for
natural methane emissions that can be released from the Arctic tundra,
as it allows it to be put in relation to the much larger release of
methane emissions from human activities. Although estimates of the
release of methane from natural sources in the Arctic and estimates of
methane from human activity have been presented separately in previous
studies, this is the first time that the relative contribution of the
two sources to global warming has been quantified and compared.
"It is important to put the two estimates alongside each other to point
out how important it is to urgently address methane emissions from
human
activities, in particular through a phase out of fossil fuels. It is
important for everyone concerned about global warming to know that
humans are the main source of methane emissions and that if we can
control humans' release of methane, the problem of methane released
from
the thawing Arctic tundra is likely to remain manageable," explains
Lena
Höglund-Isaksson, a senior researcher with the IIASA Air Quality and
Greenhouse Gases Program and one of the authors of the study published
in Nature Scientific Reports earlier this week.
According to the researchers, their findings confirm the urgency of a
transition away from a fossil fuel based society as well as the
importance of reducing methane emissions from other sources, in
particular livestock and waste. The results indicate that man-made
emissions can be reduced sufficiently to limit methane-caused climate
warming by 2100 even in the case of an uncontrolled natural Arctic
methane emission feedback. This will however require a committed,
global
effort towards substantial, but feasible reductions.
"In essence, we want to convey the message that the release of methane
from human activities is something we can do something about,
especially
since the technology for drastic reductions is readily available—often
even at a low cost. If we can only get the human emissions under
control, the natural emissions should not have to be of major concern,"
concludes Höglund-Isaksson.
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