12 replies to this topic

[jugoso]

The Arctic Sea is experiencing rapid ice loss at a pace so fast that the area will soon be ice-free in warmer months, scientists confirmed in a report this week—showing a collapse in total sea ice volume to one fifth of its level in 1980.
The alarming rate of melting was measured by the European Space Agency’s CryoSat-2 satellite, which uses new technology to measure the thickness of the sea ice in addition to how much of the region is covered.

The newly released data confirms earlier reports—which included data from NASA's ICESat satellite between 2003 to 2008—that the Arctic, which normally maintains vast amounts of ice throughout the year, may soon be ice-free during warmer months. Another team of scientists came to the same conclusion in September using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the University of Washington’s Polar Science Center.
Researchers published the study online in Geophysical Research Letters. "Other people had argued that 75 to 80 percent ice volume loss was too aggressive," said co-author Axel Schweiger in a press release. "What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid.
http://www.commondre...ne/2013/02/15-6

[Frank Merton]

The loss of Arctic Sea ice is not of the same order of problem as the loss of glacial ice, as the water from the melt does not go to raising sea levels around the world (the melted ice was displacing water anyway).  Indeed, by opening shorter sea-lanes, it may actually help reduce CO2 emissions.

What it really is is a serious harbinger of other consequences of the warming and clear evidence of it.  I read an article today of serious tundra warming in Siberia -- warming that could lead to significant releases of methane into the atmosphere.  The world will probably work its way through the warming predicted for the next century, as a major expense and cause of a some disasters, but actually not that much of a catastrophe and something that will only somewhat slow human progress, provided the warming doesn't become of a run-away sort.  That is a small possibility that this methane business causes me to worry about.

[Little Fish]

AMO : Atlantic Multidecadel Oscillation :



now, what do you think the cause of arctic "ice loss" is?

and what do you think the future holds for the arctic ice given the above chart?

[Babe Ruth]

It seems "there's a bad moon on the rise"?

[Hilander]

I feel sorry for the animals like Polar Bears that depend on this sea ice for hunting.  Man has changed this planet more than anything else.

[Br Cornelius]

Little Fish, on 22 February 2013 - 06:31 PM, said:

AMO : Atlantic Multidecadel Oscillation :



now, what do you think the cause of arctic "ice loss" is?

and what do you think the future holds for the arctic ice given the above chart?

The problem is Little Fish that Arctic sea Ice and Glacial sea Ice are both lower than they have been in thousands of years and this doesn't fit at all with your cyclic AMO theory.
Let us also not forget that AMO is a climate response and not a driver.
Here's a graph which shows how poorly your AMO theory fits the known sea ice data;




http://en.wikipedia....0-part-2009.png

To put a more formal scientific slant on it;

Quote

Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may
become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires infor-
mationonthehistoryofArcticsea-iceconditionsthroughthegeologicpast.Thisinformationcanbeprovided
by proxyrecordsfrom the ArcticOcean floor and from the surroundingcoasts.Althoughexistingrecordsare
farfromcomplete,theyindicatethatseaicebecameafeatureoftheArcticby47 Ma,followingapronounced
decline in atmospheric pCO
2
after the Paleocene–Eocene Thermal Optimum, and consistently covered at
least part of the Arctic Ocean for no less than the last 13–14 million years. Ice was apparently most wide-
spread during the last 2–3 million years, in accordance with Earth’s overall cooler climate. Nevertheless,
episodes of considerably reduced sea ice or even seasonally ice-free conditions occurred during warmer
periods linked to orbital variations. The last low-ice event related to orbital forcing (high insolation) was in
theearlyHolocene,afterwhichthenorthernhighlatitudescooledoverall,withsomesuperimposedshorter-
term (multidecadal to millennial-scale) and lower-magnitude variability. The current reduction in Arctic ice
cover started in the late 19th century, consistent with the rapidly warming climate, and became very
pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few
thousand years and unexplainable by any of the known natural variabilities.

Arctic paleoclimate proxies in lake and marine sediments, tree
rings, and ice cores indicate that from the mid-19th century the
Arctic not only warmed by more than 1
C average in comparison
with the ‘‘Little Ice Age’’ (
Overpecket al.,1997
), but also reached the
highest temperatures in at least the last two thousand years
(
Kaufman et al., 2009
). This warming sharply reversed the long-
term cooling trend that had likely been caused by the orbitally-
driven decreasing summer insolation with the positive feedbacks
from ice and snow albedo (e.g.,
Otto-Bliesner et al., 2006b
).
Subglacial material exposed by retreating glaciers in the Canadian
Arctic corroborates that modern temperatures are higher than any
time in at least the past 1600 years (
Anderson et al., 2008
). An even
longer perspective for the outstanding magnitude of the modern
warmingandrelatedicelossisprovidedbythehistoryoficeshelves
at the northern coast of Ellsemere Island, which are made of super-
thickened landfast ice supported by pack ice in the adjacent Arctic
Ocean.These ice shelves have been stable for most of the last5.5 kyr
basedondriftwoodages(
Englandetal.,2008
),butdeclinedbymore
than90%duringthe 20thcenturyandcontinuetobreakatanotable
rate (
Mueller et al., 2008
).
An unraveled magnitude and duration of modern sea-ice retreat
on a millennial background has been reported for the Nordic Seas
based on combined ice core and tree-ring proxy data from Svalbard
and Scandinavia (
Macias-Fauria et al., 2009
). A comparison of this
reconstruction with the Arctic-wide compilation of ice extent since
the mid-19th century (
Kinnard et al., 2008
) shows a close match
except for an obvious discrepancy in the early 20th century
(
Fig. 12
). This discrepancy reflects the pronounced warming event
in the Nordic Seas that was amplified by multidecadal variability of
the North Atlantic circulation (
Polyakov et al., 2009
) and therefore
affected primarily the Atlantic sector of the Arctic, somewhat
similar tothe 15th-century warming anomaly (
Crespin et al., 2009
).
In contrast, a very close match between the Nordic Seas and Arctic-
wide records of ice extent during the recent decades emphasizes
the pan-Arctic nature of the modern ice loss

http://www.geo.umass...R10 inpress.pdf

Far from the climate community denying the contribution of the AMO in causing changes in sea ice, they acknowledge it and account for it in their calculations of the current AGW induced decline.

Would you like a straw with your slushy sir


Br Cornelius

Edited by Br Cornelius, 23 February 2013 - 10:13 AM.

[Little Fish]

Br Cornelius, on 23 February 2013 - 09:16 AM, said:

The problem is Little Fish that Arctic sea Ice and Glacial sea Ice are both lower than they have been in thousands of years and this doesn't fit at all with your cyclic AMO theory.
Let us also not forget that AMO is a climate response and not a driver.
Here's a graph which shows how poorly your AMO theory fits the known sea ice data;




http://en.wikipedia....0-part-2009.png

so how do you account for this:



it shows a 2m km2 increase in arctic ice from 1975-1980 which is not shown on your chart :

Quote

Would you like a straw with your slushy sir

i don't know what you mean by that, but i'd bet you touched yourself when you typed it.

[Br Cornelius]

You do understand about running means??
Your also attempting that old trick of selecting your frame of reference to misrepresent the overall dataset. Always ends badly. The larger dataset clearly shows the downward trend after smoothing for outliers which is standard stats. Concentrat6ing on the extreme outliers is also a standard deniers trick - again, it always ends badly when you look at the bigger picture.

Also, my source was Wiki, how about yours. Its meaningless without been able to verify.


Br Cornelius

Edited by Br Cornelius, 24 February 2013 - 07:12 PM.

[Br Cornelius]

Frankly I cant believe we are going down this path "again" of attempting to use outliers to disprove a clear and overwhelming trend.

Pathetic.

Maybe you'd like to deny the evidence of your own eyes;



Br Cornelius

Edited by Br Cornelius, 24 February 2013 - 08:40 PM.

[Little Fish]

your 2012 data is one year, by your own reckoning that should be an outlier, why wasn't that "smoothed out"?

[Br Cornelius]

Little Fish, on 24 February 2013 - 09:25 PM, said:

your 2012 data is one year, by your own reckoning that should be an outlier, why wasn't that "smoothed out"?

Look at the trend, visible since 1979 up to today. I am not interested in 2012 in isolation.

However, what is far more significant is the downward trend in Arctic glacial ice (the stable stuff) which is at its lowest ebb for thousands of years (Baffin Island again).

Br Cornelius

Edited by Br Cornelius, 24 February 2013 - 09:41 PM.

[Little Fish]

Br Cornelius, on 24 February 2013 - 09:31 PM, said:

Look at the trend, visible since 1979 up to today. I am not interested in 2012 in isolation.

Br Cornelius

your wiki graph is certainly interested in the 2012 data since it didn't smooth it, yet managed to reverse the trend from 1975 yo 1980 by smoothing it according to you.
do you think 30 years of data is relevant given the 70 year amo cycle going on.
do you accept the wikipedia graph uncritically previous to 1979?
as you know antartica ice has been increasing so this doesn't look like "global" warming.

[Br Cornelius]

Little Fish, on 24 February 2013 - 09:46 PM, said:

your wiki graph is certainly interested in the 2012 data since it didn't smooth it, yet managed to reverse the trend from 1975 yo 1980 by smoothing it according to you.
do you think 30 years of data is relevant given the 70 year amo cycle going on.
do you accept the wikipedia graph uncritically previous to 1979?
as you know antartica ice has been increasing so this doesn't look like "global" warming.

Antarctic has not changed within standard error of recording;


Did you see it growing in any meaningful way ??
I really don't understand your point about the change in smoothing - since the whole datasets are smoothed throughout in exactly the same way. The trend through out the good data period is clearly downwards, and the less strong data is also downwards. Its not as if it is insignificant data since it was been recorded right back over 100years - just not by satellite. People have been living round, navigating and trading across this region for hundreds of years, so this is not suddenly a new undiscovered territory.
The data back beyond the 1979 point is certainly less compelling when it comes to sea ice since it is far more patchy. However the glacial arctic ice is at a  millennial low, which is verified by much stronger data and shows a clearly warmer arctic than for centuries.

If you want to understand whats really going on in the Arctic go and read the scientific paper I linked to, it goes into extreme detail. However I suspect you have no interest in understanding anything about the Arctic.

Br Cornelius

Edited by Br Cornelius, 24 February 2013 - 10:16 PM.