The media is getting excited again over our rapidly disappearing sea
ice which blew past the 2007 record and bettered it by 500,000 square
kilometes to hit a total of 3,400,000 sq kilometers.
In fact my prediction of 2007, before the record was particularly
apparent then has been powerfully confirmed as the Arctic sea ice has
now clearly entered its terminal stage of breakup and collapse. It
is quite reasonable to expect almost all winter ice to melt out each
summer well before the end of the decade.
We also have hard confirmation that this has been brought about by a
warm water distribution shift into the North Atlantic from the
Southern Hemisphere. Understand that this has nothing to do from
imagined global warming or CO2 production.
The media of course will continue to babble about the end of the
world as we know it.
It is quite plausible though that we may return to Bronze Age
conditions. We have certainly seen a recovery of Medieval Warm Spell
conditions. This all fits well with a thousand year cycle brought
about possibly by a strong variation in the flux of cold waters into
the Deep in the Antarctic. That is the one thing that I can identify
as having the real power to do all this. Major aspects of these
waters are in fact changing. Whatever is happening, the circumpolar
current is drawing a lot less heat and the ice is expanding there.
The result has been to dump surplus heat into the north Atlantic for
the past forty years or so. This has now destroyed or weakened all
the multiyear ice in the Arctic setting up the present collapse.
Arctic Ice “Rotten”
to the North Pole, scientist says
By Margaret
Munro September 21, 2012
NASA handout image
shows how satellite data reveals how the new record low Arctic sea
ice extent, from September 16, 2012, compares to the average minimum
extent over the past 30 years (in yellow). Sea ice extent maps are
derived from data captured by the Scanning Multichannel Microwave
Radiometer aboard NASA's Nimbus-7 satellite and the Special Sensor
Microwave Imager on multiple satellites from the Defense
Meteorological Satellite Program. (REUTERS/NASA/Goddard Scientific
Visualization Studio/Handout)
http://www.vancouversun.com/news/national/Arctic+Rotten+North+Pole+scientist+says/7279002/story.html
When David Barber
first headed to the Arctic in the 1980s, the ice would typically
retreat just a few a kilometres offshore by summer’s end.
Now he and his
colleagues have to travel more than 1,000 kilometres north into the
Beaufort Sea to even find the ice.
And it’s nothing
like the thick, impenetrable ice of Arctic lore.
This year the ice is
“rotten” practically all the way to the North Pole, says Barber,
a veteran Arctic researcher and director of the Centre for Earth
Observation Science at the University of Manitoba.
“The multi-year ice,
what’s left of it, is so heavily decayed that it’s really no
longer a barrier to transportation,” he says, explaining how melt
ponds have left much of the ice looking like Swiss cheese.
“You could have
taken a ship right across the North Pole this year,” says Barber,
whose research team was involved in a 36-day research cruise in the
Beaufort on a Canadian Coast Guard ship.
The Arctic ice loss
this summer shattered the record set in 2007. It hit the low point
last weekend, covering 3.41 million square kilometers, or 24 per
cent, of the Arctic Ocean, according to the U.S. National Snow
and Ice Data Center, which has been tracking the ice with satellites
since the late 1970s.
This year’s minimum
is nearly 50-per -cent lower than the 1979 to 2000 average.
While the ice loss
documented by the NSIDC is record-setting, Barber says the reality in
the Arctic is ever worse.
The U.S. numbers are
about “a 15-per-cent over-estimation of how much ice is actually
there,” says Barber. That’s because satellites have trouble
discerning ice conditions, he says, and will count heavily decayed
ice as solid.
Regardless of who is
doing the counting, he and other scientists consider the ice loss
remarkable. And they say the impact will be felt far beyond the
Arctic.
“It’s a globally
significant change on our planet,” Barber said in an interview.
Many expect the Arctic
could be “seasonally ice free” in the summer within a decade.
“I’d say 2020,
plus or minus five years,” says Barber.
At that point the
planet will be without its icy dome for the first time in eons.
A recent study that
looked back 1,450 years indicates the current Arctic ice melt has
already eclipsed the medieval warm period of about 1,000 years ago.
“The level that we
are at now is unprecedented over the last 1,450 years,” says
Barber. “And as far as we know we have to go back over a million
years to find a period when the Arctic was seasonally ice-free in the
summer.”
The Arctic melt is
also happening faster than at any time in the planet’s past, says
Barber, noting that the geological and historical records indicate it
took tens of thousands of years to move to a seasonally-ice-free
Arctic in the past.
“Now we are getting
there in tens of years, not tens of thousands of years,” he says.
“And we don’t know how the Earth is going to respond because we
have never seen such a rapid change before.”
Environmentalists and
scientists were quick this week to call for cuts in greenhouse gas
emissions to slow the global warming that is melting the ice.
James Hansen, a
prominent and outspoken NASA climate scientist, said the Arctic
melting shows the risks society is running by failing to limit
emissions produced by burning oil, coal and gas.
“The scientific
community realizes that we have a planetary emergency,” said
Hansen. “It’s hard for the public to recognize this because they
stick their head out the window and don’t see that much going on.”
“We can see very
viscerally in the ice how warming temperatures are changing the
Earth’s environment,” Walt Meier, of U.S. NSIDC told a media
briefing this week.
He and other
researchers say the Arctic melt is just the tip of the iceberg.
Rising global
temperaturess are also transforming northern ecosystems,
melting permafrost and shattering ancient ice shelves. Giant icebergs
from the disintegrating shelves are now sailing through Canada’s
Beaufort Sea, creating a new hazard for oil rigs, says Barber, whose
team is involved in national and international efforts to get a read
on the new Arctic reality and it implications.
Global warming is also
altering the oceans. More warm, salty water from the North Atlantic
is flowing in the Arctic, and may be helping speed up ice melt.
Another concern is
rising sea level. Arctic ice is already in the ocean so does not
raise sea level when it melts. But the extra heat being absorbed by
the Arctic Ocean due to the ice loss appears to be accelerating
melting of the Greenland ice sheet, which does raise sea levels.
The growing expanse of
open Arctic water, which traps a lot more of the sun’s heat
than reflective ice, is also altering polar storms and winds,
says Barber. And this in turn may be linked to the increasingly
strange and extreme weather seen from New Orleans to Newfoundland.
Statistical evidence
suggests the changes in the Arctic are slowing the jet stream and
pushing it further south, leading to more “persistent” climate
patterns – be it rain, drought or sunshine, he says. The
challenge now is to understand the physical mechanism.
”Our society, our
civilization and how we live our lives – it’s all predicated on a
stable climate system,” says Barber, who notes that the planet has
undergone abrupt climate change in the past and could do so again.
“The take-home
message for people is we are running an experiment with Earth’s
climate system,” says Barber, and greenhouse gases are contributing
to enormous change – like melting Arctic ice – that
is happening much faster than anticipated.
Arctic expert
predicts final collapse of sea ice within four years
As sea ice shrinks to record lows, Prof Peter Wadhams warns a
'global disaster' is now unfolding in northern latitudes
one of the world's
leading ice experts has predicted the final collapse ofArctic sea
ice in summer months within four years.
In what he calls a
"global disaster" now unfolding in northern latitudes as
the sea area that freezes and melts each year shrinks to its
lowest extentever recorded, Prof Peter Wadhams of Cambridge
University calls for "urgent" consideration of new
ideas to reduce global temperatures.
In an email to the
Guardian he says: "Climate change is no longer something we
can aim to do something about in a few decades' time, and that we
must not only urgently reduce CO2 emissions but must urgently
examine other ways of slowing global warming, such as the
variousgeoengineering ideas that have been put forward."
These include
reflecting the sun's rays back into space, making clouds whiter and
seeding the ocean with minerals to absorb more CO2.
Wadhams has spent many
years collecting ice thickness data from submarines passing below the
arctic ocean. He predicted the imminent break-up of sea ice in summer
months in 2007, when the previous lowest extent of 4.17 million
square kilometres was set. This year, it has unexpectedly plunged a
further 500,000 sq km to less than 3.5m sq km. "I have been
predicting [the collapse of sea ice in summer months] for many years.
The main cause is simply global warming: as the climate has warmed
there has been less ice growth during the winter and more ice melt
during the summer.
"At first this
didn't [get] noticed; the summer ice limits slowly shrank back, at a
rate which suggested that the ice would last another 50 years or so.
But in the end the summer melt overtook the winter growth such that
the entire ice sheet melts or breaks up during the summer months.
"This collapse, I
predicted would occur in 2015-16 at which time the summer Arctic
(August to September) would become ice-free. The final collapse
towards that state is now happening and will probably be complete by
those dates".
Wadhams says the
implications are "terrible". "The positives are
increased possibility of Arctic transport, increased access to Arctic
offshore oil and gas resources. The main negative is an acceleration
of global warming."
"As the sea ice
retreats in summer the ocean warms up (to 7C in 2011) and this warms
the seabed too. The continental shelves of the Arctic are composed of
offshore permafrost, frozen sediment left over from the last ice age.
As the water warms the permafrost melts and releases huge quantities
of trapped methane, a very powerful greenhouse gas so this will give
a big boost to global warming."
No comments:
Post a Comment