Climate change, Global warming
> Glaciers, Polar regions
Illustration: Brendan Monroe
Public Attitudes About Climate Change
The Opinion Pages|Letters
APRIL 14, 2014
A crack in the ice
formed on the lagoon.
The frozen lagoon
provides the residents of Shishmaref
with access to the mainland.
Photograph: Nima Taradji
Nowhere to Go Amid
Alaska’s Melting Ice
By Rena Silverman
Mar. 4, 2016
polar regions UK
the planet's poles >
experience extreme heat USA
polar melt > rising oceans
avoid the melting of the polar ice caps
ice shelf USA
ice sheet USA
melting ice sheets UK
West Antarctic ice sheet
Paris accord rift
Cagle 4 June 2017
glaciers UK / USA
Alaskan glacier USA
climate change > warmer winters >
Himalayan glaciers UK
Captured on camera:
50 years of climate change in the
Himalayas UK 2009
Series of before and after panoramas
of Imja glacier taken five decades apart
highlights dramatic reduction
of Himalayan ice
glacial lakes UK
global warming > rising sea levels
global warming / climate change > desert cities
climate disaster UK
eco disaster UK
The world's melting glaciers
glacier melt UK
Big Melt USA
the-big-thaw-how-russia-could-dominate-a-warming-world - Dec. 16, 2020
thawing Arctic permafrost
thawing permafrost > Climate
change hits Alaska's national parks
Alaska’s melting ice
Tanzania > Mt. Kilimanjaro ice cap USA
Corpus of news articles
Earth > Climate change, Global warming
Glaciers, Polar regions
Twilight of the Glaciers
July 29, 2011
The New York Times
By STEPHEN P. NASH
AN hour or so up ahead, at the higher elevations along the
trail that leads over Siyeh Pass, huckleberries were ripening. Even a dawdling
day hiker like me knows that huckleberries can quickly mean grizzlies in Glacier
National Park. I indulged a nervous tic and patted around for the loud red
aerosol can on my belt, whose label reads Counter Assault. It’s effective as a
bear repellent, but even more reliable at making an urbanite feel faintly
I was in northwest Montana for the hikes and the huckleberries, but most of all
to experience the namesake glaciers, which, I had recently learned, might be
around for only another decade or so. Given that a century and a half ago there
were 150 and now there are 25, the trip makes me an enlistee in the practice
known by a somewhat prickly term: last-chance tourism.
For now, though, there are still glaciers to be seen. The park’s skein of
well-maintained trails traverses every section of its million-plus acres and can
accommodate any level of ability, from backpackers to the sheets-and-coverlets
crowd. Even visitors who prefer to commune with nature through a car window can
be awed by the views of the Jackson and Blackfoot Glaciers from Going-to-the-Sun
Road, the often car-choked highway that more or less bisects the park west to
And for those who want to get closer, some serious legwork over steep terrain
can put you right next to both the Grinnell and Sperry Glaciers, respectively a
day and an overnight’s hike away. There are other glaciers to be glimpsed in the
distance during a hike, but they can’t be reached by trails. These are
excursions that require ice ax, ropes or crampons: the well-sequestered Pumpelly
Glacier, for example, at 8,420 feet, and its close neighbor, the Pumpkin
Other glaciers are nearer a trail, but still display their remote and frigid
glory at some distance, and in a way the craggy surroundings make them even more
vivid. I chose the Siyeh Pass Trail because it affords a prolonged, spectacular
view of the Sexton Glacier from below.
Alpine glaciers like Sexton don’t look like peaks or cubes. A couple of miles
into the hike, as the trail opened into a valley, it came into view: a massive,
ragged smear of snow-laden ice, perched just under the sawtooth granite skyline.
My audio track, meanwhile, was the cascading water of Baring Creek, which runs
parallel to much of the trail. Descending from the glacier, it charges over a
series of red-rock ledges and then makes its way down into the azure St. Mary
Lake far below.
As the trail continued, the bottom edge of Sexton became visible — a violent
crumble, broken loose by gravity and temperature. Glaciers are forceful,
slow-flowing rivers of ice. With binoculars, I could see Sexton’s thickness and
true magnitude. The perspective also offers, if you’re up for it, a rather
stunning view into the future. As I pushed ahead, a graying volunteer ranger
approached me at a nimble gait. No bears sighted, he reported. (O.K.!) He was a
veteran of decades here, it turned out. We craned our necks up at the
still-formidable Sexton, and he said that it had once looked far larger to him.
I read later that it has, in fact, lost at least 30 percent of its surface area
since the mid-’60s.
There are several measures of what qualifies as a glacier. One generally
accepted rule of thumb is that they are a minimum of 25 acres in size. The most
recent report has Sexton at 68.
I moved on, ascending the switchbacks that pull the Siyeh trail up toward the
8,000-foot pass. I was well above tree line by now, and only a few peaks away
from the Canadian border. Not far off, out on the moraines, a quartet of
mountain goats appeared, munching and then settling.
A good idea. I was tired, too. According to Stephen Ambrose’s “Undaunted
Courage,” which follows the cross-country trek of Meriwether Lewis and William
Clark, Lewis was able to bushwhack 30 miles in a day. I was going to do 11, and
without the whacking. (The Lewis and Clark expedition came within sight of these
mountains in 1806.)
As I rested I heard women’s voices come from up the trail, sounding like an
exuberant traveling book group. They seemed delighted to find a sprawled,
worn-out guy to greet in passing. “How do you like it? This is our backyard!”
the leader announced, adding that they were from Kalispell, Mont., just
southwest of the park. I responded in superlatives, and asked whether folks here
talk much about what’s happening with the glaciers.
There was a pause and the temperature seemed to decline a degree or two. “God
will take care of everything we need,” one said.
“I don’t think man has anything to do with that,” her friend put in.
(A bartender at one of the lodges,
not-authorized-to-speak-publicly-on-the-matter, confided that not all locals
share these views.)
After a bit, they warmed enough to point out some huckleberry bushes nearby.
(This is a popular shrub around here, and not just for bears; after a few days
in the area, I can attest to the virtues of locally marketed huckleberry beer,
jam, pie, syrup, Riesling, lip balm, French toast, soda, cobbler, lemonade, ice
cream, daiquiris, tea and milkshakes.)
Retracing my steps back down to the trailhead, I was alone again — not a wise
practice, according to park brochures. Lewis recounted that one grizzly, already
shot four times through the lungs, charged and dispersed a six-man hunting party
while its stalwarts were still firing. Still, over the past hundred years, and
despite tens of millions of visitors, only 10 fatal grizzly attacks have been
recorded here. They do, however, take up a fair portion of mind space.
The Siyeh Pass Trail can either be an extended loop or a somewhat shorter out
and back of about 11 miles — the option I chose. As I headed back down into the
valley it wasn’t much of a stretch to think of the looming Sexton as alive. The
pressure of the glaciers’ weight causes the ice to flow forward over the
landscape; colder temperatures allow for a buildup of ice, which speeds up the
flow. Heat — a warmer day, season or era — is the competing force, and the
glaciers ebb. That movement is a defining feature, part of what makes glaciers
distinct from your more prosaic all-year patches of snow.
The day before, I had spoken with Daniel Fagre, who coordinates climate change
and glacial geology studies here for the United States Geological Survey. He is
a 20-year veteran of research at the park. The retreat of the glaciers began
around 1850, he said, as part of a slow, natural climatic variation, but the
disappearing act has accelerated during the last hundred years. Until recently,
his research projected that, as global warming hit its stride, the park’s
glaciers would all be gone by the year 2030. Now he thinks it may be as soon as
Outsize snows this past winter, which kept many park roads and trails closed
well into July, could briefly forestall the meltdown, but the longer warming
trend is inexorable, he said.
No reprieve? “No, I think we are continuing on that path,” he said.
The science is preliminary, but it’s clear that this loss will be more than
aesthetic for the park’s ecosystem, he said. Those glacial reservoirs provide a
steady supply of cool meltwater through hot summers and dry spells, helping to
sustain a constellation of plants and animals, some rare — big-horned sheep, elk
and mountain goats among them.
Passing again under the glacier as daylight faded, the trail neared its end.
Those prospective losses weighed heavily — nostalgia, of a sort, laced with
MORE pleasantly, the park celebrates nostalgia of a different sort — from the
Art Deco typography on the official signage to the fleet of low-slung, roll-top
tour buses known as “red jammers,” which date from the ’30s. These ply the roads
between robber-baron-era hotels, offering full- and half-day tours to various
sections of the park ($30 and up).
There’s a wealth of accommodations along the eastern and western boundaries of
the park, especially in the towns of East Glacier Park and West Glacier. Despite
their names, these towns, with populations of only a few hundred each, are more
like distant cousins than identical twins. West Glacier, half an hour from the
Kalispell airport, is generally newer, and sprawls.
East Glacier Park, two and a half hours north of the Great Falls, Mont.,
airport, is a charming, tumbleweedy throwback with a string of weathered
eateries and motor-court lodgings that are only slightly post-World War II.
There’s also the Backpacker’s Inn, a combination hostel and super-cheap motel
with a mostly youthful clientele who like the clean, spare single rooms for $30
a night. I’ve stayed in each of these places a time or two, but this night —
after a fiery, pepper-laden dinner of enchiladas pasillas at Serrano’s Mexican
restaurant among a crowd of other glacier-gawkers and local ranchers — I opted
for the Mountain Pine Motel. It has endured, with appearance and ambience
intact, since 1947. The owners are descendants of the pioneer Sherburne family
that helped settle the park area in the 1890s.
Nearby is the century-old Glacier Park Lodge, a grandly creaky log cabin writ
very large. There are three such concessioner-run legacy hotels at the park,
erected by the Great Northern Railroad to lure tourism. My favorite is the Many
Glacier Hotel, a darkly comical but generally comfortable old wooden monstrosity
with a Swiss theme (the bellhops wear lederhosen). Its broad verandas face a
transfixing view of a horizon of pinnacles that surround Swiftcurrent Lake — one
of 131 named lakes in the park (631 others are as yet unnamed; feel free to
follow my example and name a few after your friends).
When my wonderful clawfoot tub leaked onto the occupants of the room below, the
two repair-crew guys who showed up grinned and shrugged after some futile work:
that’s kind of the way this place is, they said. The only other available room
was infested with bats, and smelled like it, I was told. It was a great stay,
just the same. Half of the hotel is being renovated all this season and is
closed, along with one of the dining rooms.
The Many Glacier Hotel is also the start of one of the park’s most popular
hikes, to Grinnell Glacier. The 8- or 10-mile hike is strenuous, though less so
than the Siyeh Pass Trail, and the payoff is that you can get within a stone’s
toss of the glacier itself, the surface area of which is more than twice
I embarked with a ranger-guided group on Chief Two Guns — a trim 45-footer,
built locally and hauled up here somehow 50 years ago — for a quick trip over
Swiftcurrent Lake. Then a short walk to another boat, the even older Morning
Eagle, across Lake Josephine to the trailhead. The boats moved past a shifting
panorama of jagged rock faces, slender waterfalls, and high above, the
destination glacier. The trail is often crowded, but that scarcely registers in
these surroundings. Hikers stop to catch a breath and find it taken again by the
view out over the string of lakes, far below, fed by Grinnell’s meltwater.
Connected by cascades, each lake is a deeper blue than the one above.
After three hours of steady ascent and a final quarter-mile of hard climbing,
the trail ends at the foot of the glacier and an iceberg-studded, expanding
lake. The lake does not appear on old maps, according to the ranger. It is a
byproduct of the fact that Grinnell’s surface is 40 percent smaller than a
Above the lake, the glacier is a wide, tilted skirt of ice whose hem you can
almost touch, brilliant under the sun even when it’s dirty with wind-blown grit
by the end of the season. It seems immense, too big to disappear, and nearly
crowds everything else from consciousness. The ranger said that until a few
seasons back you could walk out onto the lower edge of it, which is too thin now
to bear human weight safely.
Seaweed-like stromatolite fossils embossed in the cracked rocks along the trail
supply a Precambrian perspective of perhaps a couple of billion years. But it is
the view out over this lake of meltwater that grabs the imagination far more
A question hangs up there with the remnant glacier, which may soon be converted
to a few patches of ice: what comes next?
Hikes and Huckleberries
GETTING THERE AND AROUND
You can reach Glacier by flying into Kalispell, Mont., and driving half an hour
to the west side of the park, or flying into Great Falls and driving two and a
half hours to reach the eastern entry point. You can also take Amtrak’s Empire
Builder from Chicago, Seattle or Tacoma, and disembark at either East Glacier
Park, Essex or West Glacier. The Going-to-the-Sun Road has been under repair
since last year, which means that traffic is often rerouted to a single lane.
This results in stops that can add 30 or 40 minutes to the usual one- or
The Logan Pass parking lot and visitor center is usually posted “Full” by
midmorning all summer, according to park staff members. A shuttle bus system
along the Going-to-the-Sun Road ferries hikers and sightseers to and from Logan
Pass and a series of trailheads.
WHERE TO STAY AND EAT
At East Glacier Park:
Both the Glacier Park Lodge and, to the north, Many Glacier Hotel (for both
406-892-2525; glacierparkinc.com/reservations.php; both from $140 a night for
two in high season) are concessioner “legacy” railroad hotels — gracious dowager
empresses that can’t help but show their age.
The Backpacker’s Inn, right behind Serrano’s Mexican Restaurant (29 Dawson
Avenue; 406-226-9392; serranosmexican.com) and under the same ownership, is $30
a night for a single room, $12 a night for the gender-segregated hostel. Clean,
quiet, spartan. Serrano’s has benches on the porch for its surplus of patrons —
a mix of locals, tourists and backpackers who line up for the chimichangas and
carne Tampico. The super-smoky habanero sauce is sold at the cash register.
At West Glacier:
The Silver Wolf Log Chalets (406-387-4448; silverwolfchalets.com; from $176) are
cabins with interior décor that is almost exclusively logs, twigs and sticks,
quiet and nicely appointed, 10 minutes from the park.
The Belton Chalet (406-888-5000; beltonchalet.com; from $155) is a lovely old
hotel with predictable advantages and limitations. Keep in mind that a railroad
line is close at hand. The restaurant is one of the best at this edge of the
In the park:
There are 13 national park campgrounds, many with views of lakes and peaks,
including those at Apgar Lake, Medicine Lake or Swiftcurrent Lake. Cook a
porterhouse or two over the iron grill, bring in a bottle of malbec and observe
all bear precautions.
A NOTE ABOUT WATER
East Glacier Park, Mont., is a small tourist town whose water system is not
reliably safe, according to state and federal authorities. Motels connected to
that system are required to post a “boil order” warning, but some don’t, which
could mean trouble if you’re unaware and brush your teeth or drink water from
the tap in your room. (Boiling kills giardia, E. coli, cryptosporidium and other
potentially illness-producing microorganisms not reliably filtered out by the
current water operation, said Shelley Nolan of the Montana Department of
A few places, including the big Glacier Park Lodge, have their own wells or
water filtration, so the water is safe to use without boiling. Restaurants
should use bottled water. So ask.
A new water treatment plant is set to begin operation soon, according to the
federal Environmental Protection Agency, but as of this writing, it’s not
certain that will occur in 2011.
STEPHEN P. NASH
is the author of “Millipedes and Moon Tigers:
Science and Policy in the Age of Extinction.”
He teaches journalism and environmental studies
at the University of Richmond.
Twilight of the Glaciers,
Warming Is Seen
as Wiping Out Most Polar Bears
September 8, 2007
The New York Times
By JOHN M. BRODER
and ANDREW C. REVKIN
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
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.
John H. Broder reported from Washington,
and Andrew C. Revkin from New York.
Warming Is Seen as
Wiping Out Most Polar Bears,
from the melting slopes of Everest
The sons of Hillary and Tenzing
speak out about climate change:
it's a reality"
Published: 06 July 2007
By Cahal Milmo and Sam Relph
Fifty-four years after Sir Edmund Hillary and Tenzing Norgay became the first
men to scale Everest, their sons have said the mountain is now so ravaged by
climate change that they would no longer recognise it.
On the eve of the Live Earth concerts this weekend, Peter Hillary and Jamling
Tenzing yesterday issued a timely warning that global warming is rapidly
changing the face of the world's highest mountain and threatening the survival
of billions of people who rely on its glaciers for drinking water.
The base camp where Sir Edmund and Norgay began their ascent is 40 metres lower
than it was in 1953. The glacier on which it stands, and those around it, are
melting at such a rate that scientists believe the mountain, whose Nepalese
name, Qomolangma, means Mother of the World, could be barren rock by 2050.
Up to 40,000 Sherpas who live at the base of the Himalayas face devastation if
vast new lakes formed by the melted ice burst and send a torrent of millions of
tons of water down the slopes.
Mr Hillary, who has himself twice reached Everest's summit, said: "Climate
change is happening. This is a fact. Base camp used to sit at 5,320 metres. This
year it was at 5,280 metres because the ice is melting from the top and side.
Base camp is sinking each year. For Sherpas living on Mount Everest this is
something they can see every day but they can't do anything about it on their
The warning came as a survey revealed that most Britons remain unconvinced about
the extent of climate change and that terrorism, crime, graffiti and even dog
mess are more pressing issues for the UK. The Ipsos-Mori poll found that 56 per
cent of people believe scientists are still debating whether human activity is
contributing to climate change. In reality, there is virtual consensus that it
Just over half of people, 51 per cent, believe climate change will have little
or no effect and more than one-third admitted they were taking no action to
reduce their carbon emissions.
Speaking before the seven Live Earth concerts, which organisers hope will be a
catalyst for action on global warming, Jamling Tenzing, who has also climbed
Everest, said the mountain was serving as an early warning of the extent to
which it is already changing the planet.
The glacier where Sir Edmund and Norgay pitched their base camp before
eventually reaching the summit at 29,000ft on 29 May 1953 has retreated three
miles in the past 20 years. Scientists believe that all glaciers in the
Himalayas, which are between half a mile and more than three miles in length,
will be reduced to small patches of ice within 50 years if trends continue.
Mr Tenzing said: "The glaciers have receded a great deal since my father's time.
There are many things he wouldn't recognise today. The glacier on which base
camp sits has melted to such a degree that it is now at a lower altitude. I
think the whole face of the mountains is changing."
The glacial retreat presents a double peril for those who live in the Himalayas
and the populations of India and China, where the water flowing from the
mountains accounts for 40 per cent of the world's fresh water.
The rapid increase in the rate of glaciers melting - from 42 metres a year in
the 40 years to 2001 to 74 metres a year in 2006 - has resulted in the formation
of huge lakes in the space of a few years.
A United Nations study of the 9,000 glacial lakes in the Himalayas found that
more than 200 are at risk of "outburst floods", unleashing thousands of cubic
metres of water per second into an area where 40,000 people live. In 1985, Lake
Dig Tsho in the Everest region released 10 million cubic metres of water in
three hours. It caused a 10-metre-high wall of water which swept away a power
station, bridges, farmland, houses, livestock and people up to 55 miles
downstream. Scientists estimate that the most dangerous lakes today are up to 20
times bigger. One of those, Imja Tsho, did not exist 50 years ago and lies
directly above the homes of 10,000 people.
The worst-case scenario according to Nepalese scientists is a cascade effect
whereby one overflowing lake empties into another, starting a chain reaction
which would kill thousands and wipe out agriculture for generations.
Peter Hillary said: "I've seen the result of glacial lakes bursting their banks
and it's just catastrophic. It's like an atomic bomb has gone off. Everywhere is
rubble. The floods of the past are unfortunately nothing compared with the size
of what we are currently threatened with."
In the longer term, scientists believe the depletion of the glaciers will
drastically reduce the flow of water into the nine major rivers fed by the
Defra recruits critic of Bush
An outspoken critic of President George Bush's approach to combating global
warming has been appointed to advise the British Government on climate change.
Bob Watson was voted out of his job chairing the United Nations-sponsored
Intergovernmental Panel on Climate Change (IPCC) five years ago after incurring
the wrath of the Bush administration. He will take over as chief scientific
adviser at the Department for the Environment, Food and Rural Affairs (Defra) in
September. The appointment was approved by Gordon Brown.
His recruitment, a week after Mr Brown took over as Prime Minister, will be seen
as further evidence the Government is trying to distance itself from Mr Bush.
Last week, he caused consternation at the White House when he appointed Sir Mark
Malloch Brown, a strong critic of US foreign policy, as minister for Africa,
Asia and the United Nations.
Dr Watson, a British-born expert on atmospheric pollution, advised former US
President Bill Clinton on the environment and worked at the World Bank before
becoming the IPCC's chairman. The US began manoeuvring to remove him shortly
after President Bush's inauguration in 2001. A year later, he was replaced by
Rajendra Pachauri, an Indian scientist.
Environmental groups uncovered a memo from the US oil corporation ExxonMobil, a
major contributor to Mr Bush's election campaign, asking the White House to
unseat Dr Watson because he had an "aggressive agenda". At the time, Dr Watson
acknowledged the US government's intervention was an "important factor" in the
campaign to oust him.
A Defra spokeswoman said: "He was the unanimous choice out of all the
A message from the
melting slopes of Everest,
Antarctica Ice Sheet Stable
June 27, 2007
Filed at 1:57 a.m. ET
The New York Times
By THE ASSOCIATED PRESS
WELLINGTON, New Zealand (AP) -- An ice sheet in Antarctica that is the
world's largest -- with enough water to raise global sea levels by 200 feet --
is relatively stable and poses no immediate threat, according to new research.
While studies of the Greenland and West Antarctic ice sheets show they are both
at risk from global warming, the East Antarctic ice sheet will ''need quite a
bit of warming'' to be affected, Andrew Mackintosh, a senior lecturer at
Victoria University, said Wednesday.
The air over the East Antarctic ice sheet, an ice mass more than 1,875 miles
across and up to 2.5 miles thick centered on the South Pole, will remain cold
enough to prevent significant melting in the near future, the New Zealand-led
But it eventually may become vulnerable to the effects of rising sea levels
driven by the melting of other ice sheets, Mackintosh's team found. Their
research was published this week in the journal Geology.
''The East Antarctic ice sheet is the largest and the coldest and is going to be
the last to respond in any great way'' to global warming, he said. ''Our
research suggests changes in sea levels due to global warming will not be caused
by changes in the East Antarctic Ice Sheet yet.''
The researchers found that from 13,000 to 7,000 years ago, when sea levels rose
by more than 330 feet, the East Antarctic ice sheet thinned by 660 feet to 1,150
feet. Rising waters during that period would have lifted the buoyant ice sheet's
edges off its rocky base, causing pieces to detach or ''calve'' and melt.
If the sheet experienced such calving again, even small changes could have a
significant impact, the researchers said.
The study -- conducted with Australia's Macquarie University and the Australian
Nuclear Science & Technology Organization -- did not predict how much sea levels
would have to rise before the sheet's edges started to break away.
Glaciologist Wendy Lawson, head of geography at Canterbury University who took
no part in the study, said the new research supported previous modeling
indicating the sheet was stable.
''There is no short-term risk as far as the overall magnitude of the East
Antarctic ice sheet goes,'' she said.
Ice Sheet Stable,
AP-Antarctica-Ice-Sheet.html - broken link
Many Arctic Plants
to Big Climate Changes,
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
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
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.
Many Arctic Plants Have
Adjusted to Big Climate Changes, Study Finds,
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