Friday 25 May 2012

The retreat of Arctic sea ice


Note, this is not from a blog post, nut from the august scientific publication, Scientific American


More Than 150,000 Methane Seeps Appear as Arctic Ice Retreats
Scientists continue to discover more and more of the powerful greenhouse gas escaping from the thawing Arctic


22 May, 2012

Scientists have found more than 150,000 sites in the Arctic where methane is seeping into the atmosphere, according to a report published Sunday in the journal Nature Geoscience.

Aerial and ground surveys in Alaska and Greenland revealed that many of the methane seeps are located in areas where glaciers are receding or permafrost is thawing as the climate warms, removing ice that has trapped the potent greenhouse gas in the ground.

Researchers at the University of Alaska and Florida State University say the amount of methane being released from the seeps now is relatively small but could grow in coming decades as climate change intensifies, shrinking the ice that has prevented ancient deposits of the heat-trapping gas from reaching the atmosphere.

"As permafrost thaws and glaciers retreat, it is going to let something out that has had a lid on it," said lead author Katey Walter Anthony of the University of Alaska.

Scientists have long known of the existence of methane seeps in the Arctic, but the new study is one of the first to map them over large areas.

Walter Anthony and her colleagues used airplanes to fly over 6,700 lakes in Alaska during the winters of 2008, 2009 and 2010.

The survey revealed 77 previously unknown seep sites, which the scientists narrowed down to 50 lakes they visited on foot.

They documented the seeps they found, using carbon-dating to determine the age of methane released at the sites. The scientists performed the same analysis at 25 lakes in western Greenland.

Seep sites in Alaska tended to occur where permafrost is thawing or at the edges of receding glaciers. In Greenland, the scientists found seeps in places where glaciers have retreated over the past 150 years, since the end of the Little Ice Age.

The researchers calculate that methane seeps in Alaska alone are releasing 250,000 metric tons of methane into the atmosphere each year, 50 to 70 percent more than previously estimated.


Here too is an interesting letter:


Okay… let’s make a quick calculation here.

>>Methane seeps in Alaska alone are releasing 250,000 metric tons of methane into the atmosphere each year<<

If we include Canada, Greenland, Scandinavia and Siberia, we may make a conservative gesstimate than at 1,500,000 yearly metric tons, Canada being about two times the size of Alaska, Greenland one, Scandinavia one, and Siberia three times the size.

Considering methane is over 20 (some say 24) times as strong as CO2 as a GHG, let us call it a 20. So this is equivalent to 30,000,000 metric tons of CO2.

This roughly doubles the total output, which is estimated at 30,000,000 (according to the IEA at http://www.iea.org/co2highlights/co2highlights.pdf) or 50,000,000 (according to IPCC at http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-ts.pdf)

So all prior models, estimates, calculations and wild goose chases must be reviewed by an increase of 50 to 100 percent.

The real problem is that this is current outgassing. There is nothing in place to avoid a total Arctic thaw, once it will only gat warmer, considering this positive (runaway) feedback loop and the albedo one (white ice reflects more sunlight than dark land or water).

This may nudge the global climate away from the small region of negative (self-regulating) feedback loop which prevails at 12 to 15 degrees. What then?

If we look at world temperatures across the ages, we notice it was almost always at either 12 to 15, or else at 24 to 28 degrees Celsius. See the graphs in the following Contrarian sites, along with their average ranges:
http://www.americanthinker.com/2009/01/co2_fairytales_in_global_warmi.html
(12 C – 22 C)

http://strongasanoxandnearlyassmart.blogspot.com.br/2011/01/for-several-years-i-have-immersed.html
(12 C – 25 C) - (this is the same as the NASA graph)

http://www.stuffintheair.com/ancient-climates.html
(12 C – 27 C)

http://earthintime.com/earthintime.html
(15 C – 22 C)

http://www.nctimes.com/app/blogs/wp/?p=5373
(12 C – 25 C)

Hence, the IPCC may be unrealistically optimistic in aiming at a 3 to 6 Celsius warming. It may be that we can only get either of the stable saddle points, the Cool (Today / Quaternary, Ordovician, Silurian and Permian) or the Warm (Cambrian, Silurian, Devonian, Carboniferous, Triassic, Jurassic, Cretaceous).

I hope I am mistaken, but we may well be headed back to the Global Tropic of the Dinos. All thanks to lovely Big Oil. We could have electric cars since the 70s, there were several inventors who vanished who have developed viable alternatives.




No comments:

Post a Comment

Note: only a member of this blog may post a comment.