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15429 |
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Date: September 28, 2018 at 17:26:24
From: Johnl, [DNS_Address]
Subject: Antarctic (and Arctic) Methane Could Escape |
URL: https://news.nationalgeographic.com/news/2012/08/120831-antarctica-methane-global-warming-science-environment/ |
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https://news.nationalgeographic.com/news/2012/08/12083
1-antarctica-methane-global-warming-science-
environment/
A huge amount of methane cathrate is under the
antarctic as well as the arctic (permafrost).
excerpts:
The researchers suggest that microbes isolated from
the rest of the world since the ice closed over them,
some 35 million years ago, have kept busy digesting
organic matter and making methane—a much more
effective greenhouse gas than carbon dioxide. [I
question the time for methane production]
…….
Antarctica has been at or near the South Pole for more
than a hundred million years, but for most of that
time the planet was much warmer than today—because
the amount of carbon dioxide in the atmosphere was
much greater. Plant and pollen fossils confirm that
the continent was covered by forests and tundra rather
than ice—around 52 million years ago there were
even palm trees. Fjords and large bays cut deep into
its interior.
Deep stacks of sediment would have accumulated in
those marine basins, as they do in coastal water
today. Inevitably, methane-producing microbes would
have been hard at work in that mud, digesting the
organic matter—around 21 trillion tons of it, the
researchers estimate. The microbes are still at it.
…….
Hydrate is strange, fragile stuff. If the pressure
drops or the temperature rises enough to take it out
of its comfort zone—for instance, because the ice
above it melts—it falls apart. The methane escapes to
the atmosphere.
That's the worry for the future. Climate scientists
have long been concerned about the positive feedback
that would result if global warming were to
destabilize huge reservoirs of methane hydrate in the
Arctic.
(Read about National Geographic Explorer Katey Walter
Anthony's work on methane in the Arctic.)
Now they have the Antarctic to think about too. Wadham
and her colleagues calculate there could be
anywhere from 70 to 390 billion tons of carbon in
hydrates under the East Antarctic ice sheet, and a few
tens of billions of tons under West Antarctica.
(The methane there may have been made by geothermal
heating of sediments rather than microbes.) That's
less than estimates for the Arctic but in the same
ballpark.
You might think the Antarctic methane would be
secure under such a thick ice cap. But the
Antarctic has been losing a lot of ice lately.
(Related: pictures of modern Antarctic warming.)
And it's precisely the glaciers covering former
marine basins that are receding the fastest because
their leading edges are being eaten away by a warming
sea. It's conceivable that before the century is
out those glaciers could recede enough to release
whatever hydrates they've been covering.
"The longer I'm in this glaciology business," said
Tulaczyk, "the more I'm willing to accept scenarios
for really rapid change."
---------------------------------------
IMO, the massive amounts of methane hydrates in both
the Arctic and the Antarctic could be released much
faster by direct hits of nuclear bombs, rather than
just by warmer weather. Which is another reason to
avoid nuclear war.
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[15432] |
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15432 |
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Date: September 28, 2018 at 22:09:26
From: Shirley/PA, [DNS_Address]
Subject: Melting Arctic Could Rapidly Unlock 'Deep Carbon' Buried in Permafros |
URL: http://www.earthboppin.net/talkshop/disasters/messages/10930.html |
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No need for nuclear war or anything else for that matter.
As Julius Caesar was told, "Alea iacta est."
In Latin meaning the die is cast, there's no turning back.
I believe our Rubicon has already been crossed, some time ago, concerning the release of methane gas. I've posted here several times on it.
There's no stopping it now.
This link is my most recent post and comments.
http://www.earthboppin.net/talkshop/disasters/messages/10930.html
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