The fuse to the Arctic methane time bomb has been burning a long time, and
without drastic emergency intervention the future is committed to planetary
catastrophe. This latest research proves are right out of time.
The Arctic methane time bomb is warming peatlands, thawing permafrost and
melting sea floor frozen solid methane hydrate.
Thawing permafrost generates its own heat so reaches a stage where the
thawing is self increasing irreversible.
This Arctic methane is at least three times all atmospheric carbon.
There is a way out, but we have to act now or there won’t be- for today's
young generation.
Our commitment is way over 1.5C.
1.5C is also the end of the coral reefs.
The ocean heat lag alone commits us to 1.4C by 2100.
Our unavoidable commitment to more warming is at least 2.4C (published).
(Ramanathan Feng 2008 PNAS On Avoiding Dangerous Anthropogenic Interference
with the Climate System) ... even the most aggressive CO2 mitigation steps
as envisioned now can only limit further additions to the committed warming,
but not reduce the already committed GHGs warming of 2.4°C.
The Ramanathan commitment is from the ocean heat lag (more than doubles
todays warming) and unmasking of air pollution aerosol cooling.
The warming incurred by the time it will take to stabilize atmospheric GHGs
and the added warming from terrestrial carbon (excludes Arctic carbon)
feedback warming has to be added to that to get the total committed warming,
which is at least 3C.
Robert Watson has stated we are committed to 3C may be up to 5C.
The World Back says we are rapidly committing ourselves to 4C.
Today’s combined national UN filed emissions reduction pledges commit us the
4.4C by 2100, and nations have not acted on these pledges (Climate
Interactive)
An emergency response now can get us below 1.5C
1) rapidly stabilize Arctic albedo snow and ice cooling and thereby Arctic
methane by regional Arctic cooling
This also prevents American food producing regions being ruined by drought.
2) zero carbon emissions mitigation on a rapid emergency basis. That is
total conversion off all fossil fuels to 100% clean energy.
Zero carbon takes care of most black carbon but there is further black
carbon mitigation from other sources of soot like biomass burning and open
cook stoves. As black carbon is second only to soot in global warming this
can drop the warming 0.5C.
Zero carbon also takes care of most ground level ozone- another much smaller
added drop of warming.
Zero carbon decarbonization could be done within 20 years by a total
conversion off all fossil fuel energy and a halt to deforestation.
Once virtual zero carbon is reached (we cannot achieve actual zero)
atmospheric CO2 concentration is stabilized.
3) World afforestation would remove and store some carbon out of the
atmosphere so achieving zero carbon – for many decades at least
4) Biochar would sink carbon for a couple of centuries.
5) Remove CO2 directly from the air (doable in theory) would maintain
negative carbon in order to drop atmospheric CO2 below 350 ppm.
It will take a hundred years for atmospheric CO2 to get below 350, but if we
act now we may leave a legacy of a sustainable future.
If we fail to act now our legacy is a short dark age and no future.
The only hope is to convince people of the planetary Arctic warming
emergency- we have to acknowledge how bad this is and then act for our
survival.
Peter C
-----Original Message-----
From: Oliver Tickell
Sent: Friday, February 22, 2013 5:56 AM
To: [log in to unmask]
Subject: Major methane release is almost inevitable - New Scientist
Abstract link
http://m.sciencemag.org/content/early/2013/02/20/science.1228729.abstract?sid=d26b1542-62e0-4aa0-9239-a82abda2d1ad
Major methane release is almost inevitable
19:00 21 February 2013 by Michael Marshall
We are on the cusp of a tipping point in the climate. If the global
climate warms another few tenths of a degree, a large expanse of the
Siberian permafrost will start to melt uncontrollably. The result: a
significant amount of extra greenhouse gases released into the
atmosphere, and a threat – ironically – to the infrastructure that
carries natural gas from Russia to Europe.The Arctic is warming faster
than the rest of the planet, and climatologists have long warned that
this will cause positive feedbacks that will speed up climate change
further. The region is home to enormous stores of organic carbon, mostly
in the form of permafrost soils and icy clathrates that trap methane – a
powerful greenhouse gas that could escape into the atmosphere.The
Siberian permafrost is a particular danger. A large region called the
Yedoma could undergo runaway decomposition once it starts to melt,
because microbes in the soil would eat the carbon and produce heat,
melting more soil and releasing ever more greenhouse gases. In short,
the melting of Yedoma is a tipping point: once it starts, there may be
no stopping it.For the first time, we have an indication of when this
could start happening. Anton Vaks of the University of Oxford in the UK
and colleagues have reconstructed the history of the Siberian permafrost
going back 500,000 years. We already know how global temperatures have
risen and fallen as ice sheets have advanced and retreated, so Vaks's
team's record of changing permafrost gives an indication of how
sensitive it is to changing temperatures.
Stalagmite record
But there is no direct record of how the permafrost has changed, so Vaks
had to find an indirect method. His team visited six caves that run
along a south-north line, with the two southernmost ones being under the
Gobi desert. Further north, three caves sit beneath a landscape of
sporadic patches of permafrost, and the northernmost cave is right at
the edge of Siberia's continuous permafrost zone.The team focused on the
500,000-year history of stalagmites and similar rock formations in the
caves. "Stalagmites only grow when water flows into caves," Vaks says.
"It cannot happen when the soil is frozen." The team used radiometric
dating to determine how old the stalagmites were. By building up a
record of when they grew, Vaks could figure out when the ground above
the caves was frozen and when it wasn't.As expected, in most of the
caves, stalagmites formed during every warm interglacial period as the
patchy permafrost melted overhead.But it took a particularly warm
interglacial, from 424,000 and 374,000 years ago, for the stalagmites in
the northernmost cave to grow – suggesting the continuous permafrost
overhead melted just once in the last 500,000 years.At the time, global
temperatures were 1.5 °C warmer than they have been in the last 10,000
years. In other words, today's permafrost is likely to become vulnerable
when we hit 1.5 °C of global warming, says Vaks."Up until this point, we
didn't have direct evidence of how this happened in past warming
periods," says Ted Schuur of the University of Florida in Gainesville.It
will be very hard to stop the permafrost degrading as a warming of
1.5 °C is not far off. Between 1850 and 2005, global temperatures rose
0.8 °C, according to the 2007 report of the Intergovernmental Panel on
Climate Change. Even if humanity stopped emitting greenhouse gases
tomorrow, temperatures would rise another 0.2 °C over the next 20 years.
That would leave a window of 0.5 °C – but in fact our emissions are
increasing. What's more, new fossil fuel power stations commit us to
several decades of emissions.
Soggy permafrost
What are the consequences? The greatest concern, says Tim Lenton of the
University of Exeter in the UK, is the regional landscape. Buildings and
infrastructure are often built on hard permafrost, and will start
subsiding. "Ice roads won't exist any more."The increasingly soggy
permafrost will also threaten the pipelines that transport Russian gas
to Europe. "The maintenance and upkeep of that infrastructure is going
to cost a lot more," says Schuur.As for the methane that could be
released into the atmosphere, Schuur estimates that emissions will be
equivalent to between 160 and 290 billion tonnes of carbon dioxide.That
sounds like a lot, but is little compared to the vast amount humans are
likely to emit, says Lenton. "The signal's going to be swamped by fossil
fuel [emissions]."He says the dangers of the permafrost greenhouse gases
have been overhyped, particularly as much of the methane will
be converted to carbon dioxide by microbes in the soil, leading to a
slower warming effect.Schurr agrees with Lenton that the methane
emissions are "not a runaway effect but an additional source that is not
accounted in current climate models".Journal reference: Science, DOI:
10.1126/science.1228729
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