Melting ice opens up North-west
and North-east passages simultaneously.
Scientists warn Arctic icecap
is entering a 'death spiral'
Sunday, 31 August 2008
The Independent on Sunday
By Geoffrey Lean,
Environment Editor
Open water now stretches all the way round the Arctic, making it possible for
the first time in human history to circumnavigate the North Pole, The
Independent on Sunday can reveal. New satellite images, taken only two days ago,
show that melting ice last week opened up both the fabled North-west and
North-east passages, in the most important geographical landmark to date to
signal the unexpectedly rapid progress of global warming.
Last night Professor Mark Serreze, a sea ice specialist at the official US
National Snow and Ice Data Center (NSIDC), hailed the publication of the images
– on an obscure website by scientists at the University of Bremen, Germany – as
"a historic event", and said that it provided further evidence that the Arctic
icecap may now have entered a "death spiral". Some scientists predict that it
could vanish altogether in summer within five years, a process that would, in
itself, greatly accelerate.
But Sarah Palin, John McCain's new running mate, holds that the scientific
consensus that global warming is melting Arctic ice is unreliable.
The opening of the passages – eagerly awaited by shipping companies who hope to
cut thousands of miles off their routes by sailing round the north of Canada and
Russia – is only the greatest of a host of ominous signs this month of a
gathering crisis in the Arctic. Early last week the NSDIC warned that, over the
next few weeks, the total extent of sea ice in the Arctic may shrink to below
the record low reached last year – itself a massive 200,000 square miles less
than the previous worst year, 2005.
Four weeks ago, tourists had to be evacuated from Baffin Island's Auyuittuq
National Park because of flooding from thawing glaciers. Auyuittuq means "land
that never melts".
Two weeks later, in an unprecedented sighting, nine stranded polar bears were
seen off Alaska trying to swim 400 miles north to the retreating icecap edge.
Ten days ago massive cracking was reported in the Petermann glacier in the far
north of Greenland, an area apparently previously unaffected by global warming.
But it is the simultaneous opening – for the first time in at least 125,000
years – of the North-west passage around Canada and the North-east passage
around Russia that promises to deliver much the greatest shock. Until recently
both had been blocked by ice since the beginning of the last Ice Age.
In 2005, the North-east passage opened, while the western one remained closed,
and last year their positions were reversed. But the images, gathered by Nasa
using microwave sensors that penetrate clouds, show that the North-west passage
opened last weekend and that the last blockage on the north- eastern one – a
tongue of ice stretching down to Russia across Siberia's Laptev Sea – dissolved
a few days later.
"The passages are open," said Professor Serreze, though he cautioned that
official bodies would be reluctant to confirm this for fear of lawsuits if ships
encountered ice after being encouraged to enter them. "It's a historic event. We
are going to see this more and more as the years go by."
Shipping companies are already getting ready to exploit the new routes. The
Bremen-based Beluga Group says it will send the first ship through the
North-east passage – cutting 4,000 nautical miles off the voyage from Germany to
Japan – next year. And Canada's Prime Minister, Stephen Harper, last week
announced that all foreign ships entering the North-west passage should report
to his government – a move bound to be resisted by the US, which regards it as
an international waterway.
But scientists say that such disputes will soon become irrelevant if the ice
continues to melt at present rates, making it possible to sail right across the
North Pole. They have long regarded the disappearance of the icecap as
inevitable as global warming takes hold, though until recently it was not
expected until around 2070.
Many scientists now predict that the Arctic ocean will be ice-free in summer by
2030 – and a landmark study this year by Professor Wieslaw Maslowski at the
Naval Postgraduate School in Monterey, California, concluded that there will be
no ice between mid-July and mid-September as early as 2013.
The tipping point, experts believe, was the record loss of ice last year,
reaching a level not expected to occur until 2050. Sceptics then dismissed the
unprecedented melting as a freak event, and it was indeed made worse by wind
currents and other natural weather patterns.
Conditions were better this year – it has been cooler, particularly last winter
– and for a while it looked as if the ice loss would not be so bad. But this
month the melting accelerated. Last week it shrank to below the 2005 level and
the European Space Agency said: "A new record low could be reached in a matter
of weeks."
Four weeks ago, a seven-year study at the University of Alberta reported that –
besides shrinking in area – the thickness of the ice had dropped by half in just
six years. It suggested that the region had "transitioned into a different
climatic state where completely ice-free summers would soon become normal".
The process feeds on itself. As white ice is replaced by sea, the dark surface
absorbs more heat, warming the ocean and melting more ice.
NARSARSUAQ, Greenland — A strange thing is happening at the edge of Poul
Bjerge’s forest, a place so minute and unexpected that it brings to mind the
teeny plot of land Woody Allen’s father carries around in the film “Love and
Death.”
Its four oldest trees — in fact, the four oldest pine trees in Greenland, named
Rosenvinge’s trees after the Dutch botanist who planted them in a mad experiment
in 1893 — are waking up. After lapsing into stately, sleepy old age, they are
exhibiting new sprinklings of green at their tops, as if someone had glued on
fresh needles.
“The old ones, they’re having a second youth,” said Mr. Bjerge, 78, who has
watched the forest, called Qanasiassat, come to life, in fits and starts, since
planting most of the trees in it 50 years ago. He beamed like a proud grandson.
“They’re growing again.”
When using the words “growing” in connection with Greenland in the same
sentence, it is important to remember that although Greenland is the size of
Europe, it has only nine conifer forests like Mr. Bjerge’s, all of them
cultivated. It has only 51 farms. (They are all sheep farms, although one man is
trying to raise cattle. He has 22 cows.) Except for potatoes, the only
vegetables most Greenlanders ever eat — to the extent that they eat vegetables
at all — are imported, mostly from Denmark.
But now that the climate is warming, it is not just old trees that are growing.
A Greenlandic supermarket is stocking locally grown cauliflower, broccoli and
cabbage this year for the first time. Eight sheep farmers are growing potatoes
commercially. Five more are experimenting with vegetables. And Kenneth Hoeg, the
region’s chief agriculture adviser, says he does not see why southern Greenland
cannot eventually be full of vegetable farms and viable forests.
“If it gets warmer, a large part of southern Greenland could be like this,” Mr.
Hoeg said, walking through Qanasiassat, a boat ride from Narsarsuaq, a tiny
southern community notable mostly for having an international airport. Two and a
half acres near here of imported pines, spruces, larches and firs are plunked in
the midst of the scrubby, rocky hillside next to the fjord, as startling as a
mirage. “If it gets a little warmer, you could talk about a productive forest
with enough wood for logs,” Mr. Hoeg said.
Farther north, Greenland’s great ice sheet, a vast white landscape of 0.695
million square miles covering 80 percent of the island’s land mass, is melting
rapidly, alarmingly, with repercussions not only for the traditional way of life
on an island of 56,000 people, but also for the rest of the world. The more the
ice melts, the higher sea levels will eventually rise.
But here in the subarctic south — a land of icy water, forbidding mountains,
rocky hills, shallow soil, sudden winds and isolated communities slipped in,
almost apologetically, along a network of glacier-studded fjords, the changes
are more subtle and carry more promise.
“The limiting factor for human survival here is temperature, and there’s a lot
of benefits with a warmer climate,” Mr. Hoeg said. “We are on the frontier of
agriculture, and even a few degrees can make a difference.”
Greenland, a self-governing province of Denmark, was settled by the pugilistic
Viking Erik the Red in the 10th century, after his murderous ways got him
ejected from Iceland. Legend has it that he called it Greenland as a way to
entice others to join him, and, in fact, it was.
It was relatively green then, with forests and fertile soil, and the Vikings
grew crops and raised sheep for hundreds of years. But temperatures dropped
precipitously in the so-called Little Ice Age, which began in the 16th century,
the Norse settlers died out and agriculture was no longer possible.
Climate is a delicate matter in a place like this. A degree more of warmth here,
an inch less of rain there; these can have serious repercussions for a farmer
eking out a living raising sheep on the harsh terrain. But while temperatures
here in the south dipped in the 1980s, they have risen steadily since. Between
1961 and 1990, the average annual temperature was 33 degrees; in 2006, it was 35
degrees, according to the Danish Meteorological Institute.
Winter is coming later and leaving earlier. That means there is more time to
leave sheep in the mountains, more time to grow crops, more time to work
outdoors, more opportunity to travel by boat, since the fjords freeze later and
less frequently.
Cod, which prefer warmer waters, have started appearing off the coast again.
Ewes are having fatter lambs, and more of them every season. The growing season,
such as it is, now lasts roughly from mid-May through mid-September, about three
weeks longer than a decade ago. “Now spring is coming earlier, and you can have
earlier lambings and longer grazing periods,” said Eenoraq Frederiksen, 68, a
sheep farmer whose farm, near Qassiarsuk, is accessible by a harrowing drive
across a rudimentary road plowed in the hillside. “Young people now have a lot
of possibilities for the future.”
Scattered reports of successful strawberry crops in the odd home garden are
heard, although it helps to keep them in perspective. As Hans Gronborg, a Danish
horticulturist, put it, laughing, “They know whether they’ve harvested 20
strawberries, or 25.” He works at Upernaviarsuk, an agricultural research
station near Qaqortoq, one of the largest towns in the south. Like everywhere
else, it is accessible only by boat or helicopter. As a rule, no roads connect
Greenland towns.
As if visiting the zoo, people come from all over to gape at the varieties of
grass in the fields and to see what is growing here, among other things, 15
strains of potatoes and, for the first time, annual flowers: chrysanthemums,
violas, petunias.
Mr. Gronborg plucked a head of cauliflower from its nest of leaves. It had a
rich, almost sweet flavor — the result, he explained, of slow growth, long
summer days of 20 hours of light, and wide swings in temperature from day to
night. “It’s small, but it means you get all that flavor concentrated in
one-third the size of a regular cauliflower,” he said.
Mr. Gronborg loaded a dozen trays of vegetables into a motorboat to take them to
the supermarket in Qaqortoq. Soon, he said, restaurants will serve Greenlandic
vegetables beside Greenlandic lamb and reindeer.
“Greenlanders are hunters, and it takes time to change their way of living and
being,” he said. “But I am confident that things can grow in south Greenland.”
The Arctic ice cap shrank so much this summer that waves briefly lapped along
two long-imagined Arctic shipping routes, the Northwest Passage over Canada and
the Northern Sea Route over Russia.
Over all, the floating ice dwindled to an extent unparalleled in a century or
more, by several estimates.
Now the six-month dark season has returned to the North Pole. In the deepening
chill, new ice is already spreading over vast stretches of the Arctic Ocean.
Astonished by the summer’s changes, scientists are studying the forces that
exposed one million square miles of open water — six Californias — beyond the
average since satellites started measurements in 1979.
At a recent gathering of sea-ice experts at the University of Alaska in
Fairbanks, Hajo Eicken, a geophysicist, summarized it this way: “Our stock in
trade seems to be going away.”
Scientists are also unnerved by the summer’s implications for the future, and
their ability to predict it.
Complicating the picture, the striking Arctic change was as much a result of ice
moving as melting, many say. A new study, led by Son Nghiem at NASA’s Jet
Propulsion Laboratory and appearing this week in Geophysical Research Letters,
used satellites and buoys to show that winds since 2000 had pushed huge amounts
of thick old ice out of the Arctic basin past Greenland. The thin floes that
formed on the resulting open water melted quicker or could be shuffled together
by winds and similarly expelled, the authors said.
The pace of change has far exceeded what had been estimated by almost all the
simulations used to envision how the Arctic will respond to rising
concentrations of greenhouse gases linked to global warming. But that disconnect
can cut two ways. Are the models overly conservative? Or are they missing
natural influences that can cause wide swings in ice and temperature, thereby
dwarfing the slow background warming?
The world is paying more attention than ever.
Russia, Canada and Denmark, prompted in part by years of warming and the ice
retreat this year, ratcheted up rhetoric and actions aimed at securing sea
routes and seabed resources.
Proponents of cuts in greenhouse gases cited the meltdown as proof that human
activities are propelling a slide toward climate calamity.
Arctic experts say things are not that simple. More than a dozen experts said in
interviews that the extreme summer ice retreat had revealed at least as much
about what remains unknown in the Arctic as what is clear. Still, many of those
scientists said they were becoming convinced that the system is heading toward a
new, more watery state, and that human-caused global warming is playing a
significant role.
For one thing, experts are having trouble finding any records from Russia,
Alaska or elsewhere pointing to such a widespread Arctic ice retreat in recent
times, adding credence to the idea that humans may have tipped the balance. Many
scientists say the last substantial warming in the region, peaking in the 1930s,
mainly affected areas near Greenland and Scandinavia.
Some scientists who have long doubted that a human influence could be clearly
discerned in the Arctic’s changing climate now agree that the trend is hard to
ascribe to anything else.
“We used to argue that a lot of the variability up to the late 1990s was induced
by changes in the winds, natural changes not obviously related to global
warming,” said John Michael Wallace, a scientist at the University of
Washington. “But changes in the last few years make you have to question that.
I’m much more open to the idea that we might have passed a point where it’s
becoming essentially irreversible.”
Experts say the ice retreat is likely to be even bigger next summer because this
winter’s freeze is starting from such a huge ice deficit. At least one
researcher, Wieslaw Maslowski of the Naval Postgraduate School in Monterey,
Calif., projects a blue Arctic Ocean in summers by 2013.
In essence, Arctic waters may be behaving more like those around Antarctica,
where a broad fringe of sea ice builds each austral winter and nearly disappears
in the summer. (Reflecting the different geography and dynamics at the two
poles, there has been a slight increase in sea-ice area around Antarctica in
recent decades.)
While open Arctic waters could be a boon for shipping, fishing and oil
exploration, an annual seesawing between ice and no ice could be a particularly
harsh jolt to polar bears.
Many Arctic researchers warned that it was still far too soon to start sending
container ships over the top of the world. “Natural variations could turn around
and counteract the greenhouse-gas-forced change, perhaps stabilizing the ice for
a bit,” said Marika Holland, of the National Center for Atmospheric Research in
Boulder, Colo.
But, she added, that will not last. “Eventually the natural variations would
again reinforce the human-driven change, perhaps leading to even more rapid
retreat,” Dr. Holland said. “So I wouldn’t sign any shipping contracts for the
next 5 to 10 years, but maybe the next 20 to 30.”
While experts debate details, many agree that the vanishing act of the sea ice
this year was probably caused by superimposed forces including heat-trapping
clouds and water vapor in the air, as well as the ocean-heating influence of
unusually sunny skies in June and July. Other important factors were warm winds
flowing from Siberia around a high-pressure system parked over the ocean. The
winds not only would have melted thin ice but also pushed floes offshore where
currents and winds could push them out of the Arctic Ocean.
But another factor was probably involved, one with roots going back to about
1989. At that time, a periodic flip in winds and pressure patterns over the
Arctic Ocean, called the Arctic Oscillation, settled into a phase that tended to
stop ice from drifting in a gyre for years, so it could thicken, and instead
carried it out to the North Atlantic.
The new NASA study of expelled old ice builds on previous measurements showing
that the proportion of thick, durable floes that were at least 10 years old
dropped to 2 percent this spring from 80 percent in the spring of 1987, said
Ignatius G. Rigor, an ice expert at the University of Washington and an author
of the new NASA-led study.
Without the thick ice, which can endure months of nonstop summer sunshine, more
dark open water and thin ice absorbed solar energy, adding to melting and
delaying the winter freeze.
The thinner fresh-formed ice was also more vulnerable to melting from heat held
near the ocean surface by clouds and water vapor. This may be where the rising
influence of humans on the global climate system could be exerting the biggest
regional influence, said Jennifer A. Francis of Rutgers University.
Other Arctic experts, including Dr. Maslowski in Monterey and Igor V. Polyakov
at the University of Alaska, Fairbanks, also see a role in rising flows of warm
water entering the Arctic Ocean through the Bering Strait between Alaska and
Russia, and in deep currents running north from the Atlantic Ocean near
Scandinavia.
A host of Arctic scientists say it is too soon to know if the global greenhouse
effect has already tipped the system to a condition in which sea ice in summers
will be routinely limited to a few clotted passageways in northern Canada.
But at the university in Fairbanks — where signs of northern warming include
sinkholes from thawing permafrost around its Arctic research center — Dr. Eicken
and other experts are having a hard time conceiving a situation that could
reverse the trends.
“The Arctic may have another ace up her sleeve to help the ice grow back,” Dr.
Eicken said. “But from all we can tell right now, the means for that are quite
limited.”
September 16, 2007
Filed at 1:53 a.m. ET
The New York Times
By THE ASSOCIATED PRESS
PARIS (AP) -- Arctic ice has shrunk to the lowest level on record, new
satellite images show, raising the possibility that the Northwest Passage that
eluded famous explorers will become an open shipping lane.
The European Space Agency said nearly 200 satellite photos this month taken
together showed an ice-free passage along northern Canada, Alaska and Greenland,
and ice retreating to its lowest level since such images were first taken in
1978.
The waters are exposing unexplored resources, and vessels could trim thousands
of miles from Europe to Asia by bypassing the Panama Canal. The seasonal ebb and
flow of ice levels has already opened up a slim summer window for ships.
Leif Toudal Pedersen, of the Danish National Space Center, said that Arctic ice
has shrunk to some 1 million square miles. The previous low was 1.5 million
square miles, in 2005.
''The strong reduction in just one year certainly raises flags that the ice (in
summer) may disappear much sooner than expected,'' Pedersen said in an ESA
statement posted on its Web site Friday.
Pedersen said the extreme retreat this year suggested the passage could fully
open sooner than expected -- but ESA did not say when that might be. Efforts to
contact ESA officials in Paris and Noordwik, the Netherlands, were unsuccessful
Saturday.
A U.N. panel on climate change has predicted that polar regions could be
virtually free of ice by the summer of 2070 because of rising temperatures and
sea ice decline, ESA noted.
Russia, Norway, Denmark, Canada and the United States are among countries in a
race to secure rights to the Arctic that heated up last month when Russia sent
two small submarines to plant its national flag under the North Pole. A U.S.
study has suggested as much as 25 percent of the world's undiscovered oil and
gas could be hidden in the area.
Environmentalists fear increased maritime traffic and efforts to tap natural
resources in the area could one day lead to oil spills and harm regional
wildlife.
Until now, the passage has been expected to remain closed even during reduced
ice cover by multiyear ice pack -- sea ice that remains through one or more
summers, ESA said.
Researcher Claes Ragner of Norway's Fridtjof Nansen Institute, which works on
Arctic environmental and political issues, said for now, the new opening has
only symbolic meaning for the future of sea transport.
''Routes between Scandinavia and Japan could be almost halved, and a stable and
reliable route would mean a lot to certain regions,'' he said by phone. But even
if the passage is opening up and polar ice continues to melt, it will take years
for such routes to be regular, he said.
''It won't be ice-free all year around and it won't be a stable route all
year,'' Ragner said. ''The greatest wish for sea transportation is streamlined
and stable routes.''
''Shorter transport routes means less pollution if you can ship products from A
to B on the shortest route,'' he said, ''but the fact that the polar ice is
melting away is not good for the world in that we're losing the Arctic and the
animal life there.''
The opening observed this week was not the most direct waterway, ESA said. That
would be through northern Canada along the coast of Siberia, which remains
partially blocked.
WASHINGTON, Sept. 7 — Two-thirds of the world’s polar bears will disappear by
2050, even under moderate projections for shrinking summer sea ice caused by
greenhouse gases in the atmosphere, government scientists reported on Friday.
The finding is part of a yearlong review of the effects of climate and ice
changes on polar bears to help determine whether they should be protected under
the Endangered Species Act. Scientists estimate the current polar bear
population at 22,000.
The report, which the United States Geological Survey released here, offers
stark prospects for polar bears as the world grows warmer.
The scientists concluded that, while the bears were not likely to be driven to
extinction, they would be largely relegated to the Arctic archipelago of Canada
and spots off the northern Greenland coast, where summer sea ice tends to
persist even in warm summers like this one, a shrinking that could be enough to
reduce the bear population by two-thirds.
The bears would disappear entirely from Alaska, the study said.
“As the sea ice goes, so goes the polar bear,” said Steven Amstrup, lead
biologist for the survey team.
The report was released as President Bush was in Australia meeting with Asian
leaders to try to agree on a strategy to address global warming. Mr. Bush will
be host to major industrial nations in Washington this month to discuss the
framework for a treaty on climate change.
The United Nations plans to devote its general assembly in the fall to global
warming.
A spokeswoman for the White House declined to comment on the report, saying it
was part of decision making at the Interior Department, parent of the survey.
In the report, the team said, “Sea ice conditions would have to be substantially
better than even the most conservative computer simulations of warming and sea
ice” to avoid the anticipated drop in bear population.
In a conference call with reporters, the scientists also said the momentum to a
warmer world with less Arctic sea ice — and fewer bears — would be largely
unavoidable at least for decades, no matter what happened with emissions of
heat-trapping gases like carbon dioxide.
“Despite any mitigation of greenhouse gases, we’re going to see the same amount
of energy in the system for 20, 30 or 40 years,” said Mark Myers, the survey
director. “We would not expect to see any significant change in polar conditions
regardless of mitigation.”
In other words, even in the unlikely event that all the major economies were to
agree to rapid and drastic reductions in emissions of carbon dioxide and other
heat-trapping gases, the floating Arctic ice cap will continue to shrink at a
rapid pace for the next 50 years, wiping out much of the bears’ habitat.
The report makes no recommendation on listing the bears as a threatened species
or taking any action to slow ice cap damage. Such decisions are up to another
Interior Department agency, the Fish and Wildlife Service, which enforces the
Endangered Species Act. That decision is due in January, officials have said.
The wildlife agency had to make a determination on the status of a threatened
species because of a suit by environmental groups like Greenpeace and the
Natural Resources Defense Council.
In some places, the bears have adapted to eating a wide range of food like snow
geese and garbage. But the survey team said their fate was 84 percent linked to
the extent of sea ice.
Separate studies of trends in Arctic sea ice by academic and government teams
have solidified a picture of shrinking area in summers for decades to come.
A fresh analysis by scientists of the National Oceanic and Atmospheric
Administration, to be published Saturday in the journal Geophysical Research
Letters, says sea-ice coverage of the Arctic Ocean will decline by more than 40
percent before the summer of 2050, compared with the average ice extent from
1979 to 1999.
This summer the ice retreated much farther and faster than in any year since
satellite tracking began in 1979, several Arctic research groups said.
June 15, 2007
The New York Times
By ANDREW C. REVKIN
Many Arctic plant species have readily adjusted to big climate changes,
repeatedly recolonizing the rugged islands of the remote Svalbard archipelago
off Norway’s coast through 20,000 years of warm and cool spells since the frigid
peak of the last ice age, researchers report in today’s issue of the journal
Science.
Their finding implies that, in the Arctic at least, plants may be able to shift
long distances to follow the climate conditions for which they are best adapted
as those conditions move under the influence of human-caused global warming, the
researchers and some independent experts said.
Some experts on climate and biology who were not involved with the study, which
was led by scientists from the University of Oslo, said it provided a glimmer of
optimism in the face of generally bleak scientific assessments of the
vulnerability of ecosystems to the atmospheric buildup of greenhouse gases.
Terry L. Root, a biologist at Stanford who has been involved with many studies
concluding that plants and animals are measurably feeling the effects of
human-driven warming, described the Svalbard research as “great news.”
“The large number of documented changes has created quite a concern about the
fate of many species,” Dr. Root said. The new study, she said, shows that “some
Arctic plants, and hopefully vegetation in other areas, apparently are able to
respond in a manner that compensates for the rapid warming.”
Norwegian and French scientists analyzed the DNA of more than 4,000 samples of
nine flowering plant species from Svalbard, a group of islands between the
Scandinavian mainland and the North Pole. They said they found genetic patterns
that could be explained only by the repeated re-establishment of plant
communities after the arrival of seeds or plant fragments from Russia, Greenland
or other Arctic regions hundreds of miles away.
The wide dispersal of the plants presumably occurs through a combination of
Arctic winds, driftwood or dirt carried in floating ice and bird droppings, the
scientists said.
Julie Brigham-Grette, a geosciences professor at the University of
Massachusetts, said the findings were consistent with research from Alaska
showing that forests had extended farther north during a period, warmer than the
present, that peaked around 11,000 years ago.
“As the proper habitat is available, plants will survive,” she said. “I have not
seen this demonstrated so clearly as it is in this paper. If dispersal is not a
limiting factor, then maybe the rate of warming ongoing in the Arctic will not
be a limiting factor in plant survival in distant places.”
Inger Greve Alsos, the study’s lead author, said natural adaptability in the
plants might be tested if the projections for rapid Arctic warming from the
United Nations Intergovernmental Panel on Climate Change came to pass. She also
cautioned that the evidence for resilience and long-distance mobility in Arctic
plants could be the exception, not the rule.
The ability of Arctic flora to disperse widely is probably an evolutionary
consequence of the region’s tendency toward sharp climate swings, she said.
May 1, 2007
The New York Times
By ANDREW C. REVKIN
Climate scientists may have significantly underestimated the power of global
warming from human-generated heat-trapping gases to shrink the cap of sea ice
floating on the Arctic Ocean, according to a new study of polar trends.
The study, published online today in Geophysical Research Letters, concluded
that an open-water Arctic in summers could be more likely in this century than
had been estimated in the latest international review of climate research
released in February by the United Nations Intergovernmental Panel on Climate
Change.
“There are huge changes going on,” said Julienne Stroeve, a lead author of the
new study and a researcher at the National Snow and Ice Data Center in Boulder,
Colo. “Just with warm waters entering the Arctic, combined with warming air
temperatures, this is wreaking havoc on the sea ice, really.”
The intergovernmental panel concluded that if emissions of heat-trapping gases
like carbon dioxide were not significantly reduced, the region could end up
bereft of floating ice in summers sometime between 2050 and the early decades of
the next century.
For the new study, Dr. Stroeve and others at the ice center reviewed nearly six
decades of measurements by ships, airplanes and satellites estimating the
maximum and minimum area of Arctic sea ice, which typically expands most in
March and shrinks most in September.
With an expert from the National Center for Atmospheric Research, also in
Boulder, they then compared the observed trends with the projections made for
the climate panel’s review using the world’s most advanced computer models of
climate.
Dr. Stroeve’s team found that since 1953 the area of sea ice in September has
declined at an average rate of 7.8 percent per decade. Computer climate
simulations of the same period had an average rate of ice loss of 2.5 percent
per decade.
The finding implies that the Arctic ice may be quicker to respond to warming as
concentrations of heat-trapping gases rise in coming decades, said Marika
Holland, an author of the new paper and a computer modeler at the Boulder
climate center.
The map of Greenland will have to be redrawn. A new island has appeared off
its coast, suddenly separated from the mainland by the melting of Greenland's
enormous ice sheet, a development that is being seen as the most alarming sign
of global warming.
Several miles long, the island was once thought to be the tip of a peninsula
halfway up Greenland's remote east coast but a glacier joining it to the
mainland has melted away completely, leaving it surrounded by sea.
Shaped like a three-fingered hand some 400 miles north of the Arctic Circle, it
has been discovered by a veteran American explorer and Greenland expert, Dennis
Schmitt, who has named it Warming Island (Or Uunartoq Qeqertoq in Inuit, the
Eskimo language, that he speaks fluently).
The US Geological Survey has confirmed its existence with satellite photos, that
show it as an integral part of the Greenland coast in 1985, but linked by only a
small ice bridge in 2002, and completely separate by the summer of 2005. It is
now a striking island of high peaks and rugged rocky slopes plunging steeply to
a sea dotted with icebergs.
As the satellite pictures and the main photo which we publish today make clear,
Warming Island has been created by a quite undeniable, rapid and enormous
physical transformation and is likely to be seen around the world as a potent
symbol of the coming effects of climate change.
But it is only one more example of the disintegration of the Greenland Ice
Sheet, that scientists have begun to realise, only very recently, is proceeding
far more rapidly than anyone thought.
The second-largest ice sheet in the world (after Antarctica), if its entire 2.5
million cubic kilometres of ice were to melt, it would lead to a global sea
level rise of 7.2 metres, or more than 23 feet.
That would inundate most of the world's coastal cities, including London, swamp
vast areas of heavily-populated low-lying land in countries such as Bangladesh,
and remove several island countries such as the Maldives from the face of the
Earth. However, even a rise one tenth as great would have devastating
consequences.
Sea level rise is already accelerating. Sea levels are going up around the world
by about 3.1mm per year - the average for the period 1993-2003. That is itself
sharply up from an average of 1.8mm per year over the longer period 1961-2003.
Greenland ice now accounts for about 0.5 millimetre of the total. (Much of the
rest of the rise is coming from the expansion of the world's sea water as it
warms.)
Until two or three years ago, it was thought that the break-up of the ice sheet
might take 1,000 years or more but a series of studies and alarming observations
since 2004 have shown the disintegration is accelerating and, as a consequence,
sea level rise may be much quicker than anticipated.
Earlier computer models, researchers believe, failed to capture properly the way
the ice sheet would respond to major warming (over the past 20 years,
Greenland's air temperature has risen by 3C). The 2001 report of the UN's
Intergovernmental Panel on Climate Change was relatively reassuring, suggesting
change would be slow.
But satellite measurements of Greenland's entire land mass show that the speed
at which its glaciers are moving to the sea has increased significantly in the
past decade, with some of them moving three times faster than in the mid-1990s.
Scientists estimate that, in 1996, glaciers deposited about 50 cubic km of ice
into the sea. In 2005, it had risen to 150 cubic km of ice.
A study last year by the Jet Propulsion Laboratory of the California Institute
of Technology showed that, rather than just melting relatively slowly, the ice
sheet is showing all the signs of a mechanical break-up as glaciers slip ever
faster into the ocean, aided by the "lubricant" of meltwater forming at their
base. As the meltwater seeps down it lubricates the bases of the "outlet"
glaciers of the ice sheet, causing them to slip down surrounding valleys towards
the sea,
Another discovery has been the increase in "glacial earthquakes" caused by the
sudden movement of enormous blocks of ice within the ice sheet. The annual
number of them recorded in Greenland between 1993 and 2002 was between six and
15. In 2003, seismologists recorded 20 glacial earthquakes. In 2004, they
monitored 24 and for the first 10 months of 2005 they recorded 32. The
seismologists also found the glacial earthquakes occurred mainly during the
summer months, indicating the movements were indeed associated with rapidly
melting ice - normal "tectonic" earthquakes show no such seasonality. Of the 136
glacial quakes analysed in a report published last year, more than a third
occurred during July and August.
The creation of Warming Island appears to be entirely consistent with the
disintegrating ice sheet, coming about when the glacier bridge linking it to the
mainland simply disappeared. It was discovered by Mr Schmitt, a 60-year-old
explorer from Berkeley, California, who has known Greenland for 40 years, during
a trip he led up the remote coastline.
According to the US Geological Survey: "More islands like this may be discovered
if the Greenland Ice Sheet continues to disappear."
A self-governing dependency of Denmark, Greenland is the largest island in the
world but is inhabited by only 56,000 people, mainly Inuit. More than 80 per
cent of the land surface is covered by the ice sheet.
TORONTO (AP) -- A giant ice shelf has snapped
free from an island south of the North Pole, scientists said Thursday, citing
climate change as a ''major'' reason for the event.
The Ayles Ice Shelf -- all 41 square miles of it -- broke clear 16 months ago
from the coast of Ellesmere Island, about 500 miles south of the North Pole in
the Canadian Arctic.
Scientists discovered the event by using satellite imagery. Within one hour of
breaking free, the shelf had formed as a new ice island, leaving a trail of icy
boulders floating in its wake.
Warwick Vincent of Laval University, who studies Arctic conditions, traveled to
the newly formed ice island and couldn't believe what he saw.
''This is a dramatic and disturbing event. It shows that we are losing
remarkable features of the Canadian North that have been in place for many
thousands of years,'' Vincent said. ''We are crossing climate thresholds, and
these may signal the onset of accelerated change ahead.''
The ice shelf was one of six major shelves remaining in Canada's Arctic. They
are packed with ancient ice that is more than 3,000 years old. They float on the
sea but are connected to land.
Some scientists say it is the largest event of its kind in Canada in 30 years
and that climate change was a major element.
''It is consistent with climate change,'' Vincent said, adding that the
remaining ice shelves are 90 percent smaller than when they were first
discovered in 1906. ''We aren't able to connect all of the dots ... but
unusually warm temperatures definitely played a major role.''
Laurie Weir, who monitors ice conditions for the Canadian Ice Service, was
poring over satellite images in 2005 when she noticed that the shelf had split
and separated.
Weir notified Luke Copland, head of the new global ice lab at the University of
Ottawa, who initiated an effort to find out what happened.
Using U.S. and Canadian satellite images, as well as seismic data -- the event
registered on earthquake monitors 155 miles away -- Copland discovered that the
ice shelf collapsed in the early afternoon of Aug. 13, 2005.
Copland said the speed with which climate change has effected the ice shelves
has surprised scientists.
''Even 10 years ago scientists assumed that when global warming changes occur
that it would happen gradually so that perhaps we expected these ice shelves
just to melt away quite slowly,'' he said.
Derek Mueller, a polar researcher with Vincent's team, said the ice shelves get
weaker and weaker as temperatures rise. He visited Ellesmere Island in 2002 and
noticed that another ice shelf had cracked in half.
''We're losing our ice shelves and this a feature of the landscape that is in
danger of disappearing altogether from Canada,'' Mueller said.
Within days of breaking free, the Ayles Ice Shelf drifted about 30 miles
offshore before freezing into the sea ice. A spring thaw may bring another
concern: that warm temperatures will release the new ice island from its Arctic
grip, making it an enormous hazard for ships.
''Over the next few years this ice island could drift into populated shipping
routes,'' Weir said.
Sea ice in the Arctic last month melted to its
second lowest monthly minimum in the 29-year record of satellite measurements.
Scientists at the US National Snow and Ice Data Centre (NSIDC) in Colorado said
the total surface area covered by sea ice during September was smaller than in
any previous year apart from 2005, when it reached an all-time record minimum.
And it was only a sudden change to cool and stormy weather in August that
prevented another record low being set this September, they said.
"At this rate, the Arctic Ocean will have no ice in September by the year 2060,"
said Julienne Strove, one of the NSIDC's research scientists.
The Arctic sea ice floats on the ocean and its surface coverage varies naturally
in line with seasonal temperature changes, with an absolute minimum in summer
occurring around mid-September.
However, rising temperatures have seen a steady long-term decline in sea ice
during the summer months, with little recovery during the Arctic winter.
Summer sea ice across the entire Arctic has been dwindling steadily since
satellite measurements began in 1977. But since 2002 scientists have detected a
noticeable acceleration in the rate of summer loss, which they believe is caused
by global warming.
Mark Serreze, a senior research scientist at the NSIDC, said this summer could
easily have surpassed last year's record loss if it had not been for the change
in the weather.
"If fairly cool and stormy conditions hadn't appeared in August, slowing the
rate of summer ice loss, I feel certain that 2006 would have surpassed last
year's record low for September sea ice," Dr Serreze said.
"August broke the Arctic heatwave and slowed the melt, and storm conditions led
to wind patterns that tend to spread the existing ice over a larger area."
Arctic sea ice acts like an insulating lid on the northernmost ocean, reflecting
sunlight and preventing the water from absorbing heat and warming up.
Scientists fear that as more and more sea ice is lost, a "positive feedback"
will kick in, with the Arctic Ocean absorbing more sunlight, which will in turn
cause the loss of more sea ice.
"I'm not terribly optimistic about the future of the ice," Dr Serreze said.
"Although it would come as no surprise to see some recovery of the sea ice in
the next few years - such fluctuations are part of natural variability - the
long-term trend seems increasingly clear. As greenhouse gases continue to rise,
the Arctic will continue to lose its ice. You can't argue with the physics."
The Arctic has seen some of the largest increases in average temperatures in the
world over the past few decades, and could be one of the places hardest hit by
climate change.
"Arctic sea ice is an important climate indicator because it's so sensitive to
this initial warming trend," said Ted Scambos, a senior scientist at the Snow
and Ice Data Centre.
