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Arctic Sea Ice Hits Record Low
Titus Andronicus writes "Angela Fritz and Jeff Masters of Weather Underground analyze this year's record ongoing Arctic ice melt. Arctic sea ice extent, area, and volume are all at record lows for the post-1979 satellite era. The ice is expected to continue melting for perhaps another couple of weeks. Extreme sea ice melting might help cause greater numbers of more powerful Arctic storms, help to accelerate the melting of the Greenland ice sheet, and help to accelerate global warming itself, due to the increased absorption of solar energy into the ocean."
Uh... the data we have from ice cores go back way more than 33 years.
If you look at the IPCC report (wg1 chapter 2 page 136 although it's already starting to get a bit old), there is still a (minimal) chance that none of it is caused by CO2, because human release of aerosols cause a cooling effect. Of course there are other considerations like methane, etc. Most scientific organizations say things like, "most of the warming we've seen is caused by humans....." Although 'most' is a wiggle word that accurately represents our uncertainty on the matter.
It's also helps to take this into perspective, look at this graph, you'll see that we keep talking about the summer extent; the winter extent hasn't changed much. The past year was right up there with 1990s average. And the annual change is dramatically larger than the change in either the summer extent or the winter extent. Also, it is arguably more important to measure the thickness of the ice, rather than the extent, but a falling summer extent might suggest the thickness is shrinking as well. We are measuring that now, but only for a few years.
In any case you should check out this amazing picture from the article. Can you guess which direction the earth is spinning?
"First they came for the slanderers and i said nothing."
If you look at TFA, the record low that was just surpassed was set between 2006 and 2009. The records only go back to 1979, but the previous record low was not set in 1979; rather, the trend has been downwards ever since the satellite observations began.
If anyone doesn't get it:
Less sea ice > more air moisture > more snow.
So yes, global warming would cause the winters to be harsher in snowbound areas.
If you are measuring for only 35 years, a 35 year low does not mean only 35 years. It means at least 35 years.
But take a look at the data. It looks like a death spiral. The trend from the data is undeniable. Calling the current extent a record low sort of misses the point because the current amount of ice is a tiny fraction of what it was two decades ago.
http://hockeyschtick.blogspot.com/2012/08/new-paper-finds-deep-arctic-ocean-was.html ... 1–2C warmer than modern Arctic Intermediate Water." This finding is particularly surprising because it occurred during the last major ice age.
New paper finds deep Arctic Ocean from 50,000 to 11,000 years ago was 1–2C warmer than modern temperatures
A new paper published in Nature Geoscience finds "From about 50,000 to 11,000 years ago, the central Arctic Basin from 1,000 to 2,500 meters deep was
Deep Arctic Ocean warming during the last glacial cycle
T. M. Cronin, G. S. Dwyer, J. Farmer, H. A. Bauch, R. F.
Spielhagen, M. Jakobsson, J. Nilsson, W. M. Briggs Jr &
A. Stepanova
Nature Geoscience (2012) doi:10.1038/ngeo1557
In the Arctic Ocean, the cold and relatively fresh water
beneath the sea ice is separated from the underlying warmer
and saltier Atlantic Layer by a halocline. Ongoing sea ice
loss and warming in the Arctic Ocean have
demonstrated the instability of the halocline, with
implications for further sea ice loss. The stability of the
halocline through past climate variations is unclear.
Here we estimate intermediate water temperatures over the
past 50,000 years from the Mg/Ca and Sr/Ca values of
ostracods from 31 Arctic sediment cores. From about 50 to
11 [thousand years] ago, the central Arctic Basin from
1,000 to 2,500m was occupied by a water mass we call
Glacial Arctic Intermediate Water. This water mass was
1–2C warmer than modern Arctic Intermediate Water,
with temperatures
peaking during or just before millennial-scale Heinrich cold
events and the Younger Dryas cold interval. We use
numerical modelling to show that the intermediate depth
warming could result from the expected decrease in the flux
of fresh water to the Arctic Ocean during glacial conditions,
which would cause the halocline to deepen and push the
warm Atlantic Layer into intermediate depths. Although not
modelled, the reduced formation of cold, deep waters due to
the exposure of the Arctic continental shelf could also
contribute to the intermediate depth warming.
Paper finds Arctic sea ice extent 8,000 years ago was less than half of the 'record' low 2007 level
A paper published in Science finds summer Arctic Sea Ice extent during the Holocene Thermal Maximum 8,000 years ago was "less than half of the record low 2007 level." The paper finds a "general buildup of sea ice from ~ 6,000 years before the present" which reached a maximum during the Little Ice Age and "attained its present (year 2000) extent at 4,000 years before the present"
http://hockeyschtick.blogspot.com/2012/08/paper-finds-arctic-sea-ice-extent-8000.html
A 10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach
Svend Funder1,*, Hugues Goosse2, Hans Jepsen1, Eigil Kaas3, Kurt H. Kjær1, Niels J. Korsgaard1, Nicolaj K. Larsen4, Hans Linderson5, Astrid Lyså6, Per Möller5, Jesper Olsen7, Eske Willerslev1
+
ABSTRACT
We present a sea-ice record from northern Greenland covering the past 10,000 years. Multiyear sea ice reached a minimum between ~8500 and 6000 years ago, when the limit of year-round sea ice at the coast of Greenland was located ~1000 kilometers to the north of its present position. The subsequent increase in multiyear sea ice culminated during the past 2500 years and is linked to an increase in ice export from the western Arctic and higher variability of ice-drift routes. When the ice was at its minimum in northern Greenland, it greatly increased at El
As a side note from just across the strait here in Iceland, it's been abnormally warm this summer. Was kind of shocking, the peak of Snæfellsjökull (visible from Reykjavík on a clear day) showed through the ice cap. It's never happened before in recorded history. I mean, it was one thing when Iceland got a new tallest waterfall because of the retreating glaciers in Skaftafell, but to see a mountain whose name literally translates as "Snow Mountain" lose so much that its peak became visible... they're saying that at the current rate it's losing ice, the entire glacier will be gone in 20-30 years, and all of Iceland's glaciers in 150-200 years. Just crazy when you think about it, given that one of Iceland's glaciers alone is the largest in Europe by volume and takes up nearly 10% of the country.
Alanis, you oughta know: she's older than you, more mature than you, and can show some restraint in a theater
I work on coal-bearing forests in the Carboniferous (yeah, yeah, saying "in" is standard geology terminology -- I don't *actually* have a time machine), and this is the first I've heard of any type of fungus being responsible for that much change. There is a big change globally in climate as you go from the Carboniferous Period (named such because of the abundance of coal) into the Permian Period. The climate generally becomes more arid. But this is thought to be related to the development of Pangaea and the whole-hemisphere ocean on the other side of it, Panthalassa, not some transformation of forest terrains due to evolution of a new fungus. For that matter, there *are* coals in the Permian, but they are located in places such as India and Australia that people may not be as familiar with. There is also plenty of coal in rocks of all ages from the Carboniferous onward, although it's global abundance does wax and wane with global climate. For example, coal is particularly abundant in the Cretaceous Period and in the Eocene, both times of "greenhouse" conditions. It's less common in, say, the Triassic, which like the Permian has more widespread arid conditions (Pangaea was still breaking up). Coal is forming today as peat in many parts of the world. I have no doubt that the evolution of fungus that could metabolize cellulose was an important event, but it did not result in the end of coal.