Forecast Earth : Alaska Meltdown

How is global warming affecting the Alaskan climate?

Global warming in Alaska?

By Dr. Heidi Cullen, Climate Expert at: The Weather Channel

Editor’s Note: In May 2004, Dr. Heidi Cullen, climate expert at The Weather Channel, took off for Alaska to investigate the issue of global warming first hand. The following report is a portion of what she discovered.

It’s tempting to ask: "What does Alaska have to do with global warming?" The answer is simple. When you live in a place where
there is a lot of snow and ice, even a change of 1° Fahrenheit is big. It can mean the difference between frozen and not frozen. In fact, the impacts of climate change are more obvious in Alaska than
anywhere else in the United States. Many think of the state as a ’canary in a coalmine’.

Globally, Earth’s average surface temperature has
increased about 1 to 1.5° Fahrenheit over the last century. The majority of
scientists believe that this temperature increase is associated with burning
fossil fuels. Fossil fuels like oil and gas release carbon dioxide (CO2) when
combusted - adding to the greenhouse effect.

Greenhouse gases, like carbon dioxide, occur
naturally. In fact, without the greenhouse effect, Earth’s average surface
temperature would be near 0°F. The greenhouse gases that make up our atmosphere
help keep Earth’s thermostat set at a comfortable and life-sustaining 59°F. But
carbon dioxide is increasing; scientists have measured a 31 percent increase in
CO2 since 1750. When carbon dioxide increases, temperatures go up with it. A
significant portion of the observed CO2 is because of human activities, like
burning coal to produce electricity. In 1860, atmospheric CO2 was 280 parts per
million, 2004 levels have reached 379 parts per million. So while carbon
dioxide is a good thing, at the moment we have too much of a good thing - and
it’s pushing our planet into warmer territory.

Scientists have long predicted that global warming
will become visible in the form of different climate impacts. We wanted to see
these impacts for ourselves - that’s why we went to Alaska. We wanted to hear about global warming
from people who live there and have seen it for themselves.

The weather has become ’uggianaqtuq’: For centuries, native
people in the Arctic have built their lives
around the snow and ice. A central part of their traditional culture is hunting
and fishing. This requires an intimate knowledge of weather and climate.

Uggianaqtuq (OOG-gi-a-nak-took) is a North Baffin Inuktitut
word that means to behave unexpectedly, or in an unfamiliar way. From the
perspective of many hunters and elders in the Arctic,
the weather has become uggianaqtuq - a stranger - in recent years.

For the Inupiat Eskimo of Barrow, the sea ice
skirting the Arctic Ocean has been a vital
friend for hundreds of years. But it, too, is becoming a stranger - an
increasingly thin stranger. Indeed, scientists have measured a 30
percent decrease in Arctic sea ice over the past 30 years, making it a lot more
dangerous to hunt whales.

The melting of sea ice affects much more than
whaling. Some scientists predict it will lead to a seasonal opening of the
Northwest Passage, offering a potential trade route with Asia.
Ideally, ships need about 60 days of ice-free conditions for trade and
scientists say this might happen within 10 years. Animal populations in the
Last Frontier are also at risk. As the ice disappears, so does the home of the
polar bear. Some estimate the polar bear may be extinct in a few decades as the
ice it lives on eventually disappears. In fact, wildlife all across Alaska is changing. Just
by observing caribou migration patterns and bear behavior, it’s easy to see
that Alaska
is beginning to look very different from the way many people remember.

The fundamental science of global warming is solid,
but in Fairbanks,
the ground that some Alaskans stand on is not. The ground in Alaska isn’t like the ground in the lower
48. Eighty-five percent is permafrost — soil hardened with ice. Land
transportation in Alaska
is often over permafrost, which is defined as soil, rock, or sediment that has remained
below 32°F for two or more years. Increasing temperatures are making it tough
to travel these routes and its expected this will only get worse as
temperatures continue to rise.

The number of days each year that oil and gas
exploration and extraction equipment is approved for use by the Alaska
Department of Natural Resources across remote regions the tundra has gone down
from over 200 to about 100 in the past 30 years.

These changes are also affecting the 800-mile-long
Trans-Alaska Pipeline. The pipeline was originally built in 1977 for $8 billion
to transport oil from the North Slope of Alaska to Port Valdez. Because roughly
75 percent of the territory covered by the pipeline is permafrost, 420 miles
run above ground on vertical supports to avoid thawing the ground.

Scientists have cautioned that warming temperatures
could likely compromise the integrity of the pipeline. Because the vertical
supports are drilled to depths of 15 to 70 feet - there is a concern that
roughly one-third of the supports may be moving as a result of warming
temperatures and thawing permafrost. Replacing a vertical support is estimated
to cost upwards of $85,000 apiece.

And it gets worse. As the permafrost thaws, massive
amounts of CO2 and methane will be released into the atmosphere. Both are
primary greenhouse gases, and are expected to further aggravate the global
warming trend. Over the next 100 years, climate change is projected to
continue. Climate models indicate permafrost degradation in the Arctic may
occur over 10-20 percent of the present permafrost area, and the southern limit
of this frozen soil is projected to shift northward by hundreds of miles.

Erosion evicts entire town: Waves are another weapon in
the arsenal of climate impacts that are changing Alaska. For example, the town of Shishmaref, home to a little less than 600, sits on a
barrier island at the westernmost part of Alaska. This barrier island is being
swallowed by the sea at the rate of up to 125 feet a year.

And it’s taking Shishmaref with it. In Alaska, coastal erosion
is a major problem because most of the shoreline consists of permafrost covered
by tundra. Normally, permafrost melts only at the surface during the summer and
then refreezes in the winter. But now, due to global warming, the summer melt
goes deeper into the permafrost and ends up lasting well into the fall. In
addition, sea ice forms later in the season.

Sea ice serves as a protective lid for ocean waves
by helping to keep big waves in check. But now, when storms barrel through in
September and October they remain over open water. These waves break onto the
coast where thawed permafrost is vulnerable.

Warmer temperatures degrade frozen soils and sea
ice, providing a perfect example of how something can feed off itself and gain
strength. Less sea ice means stronger storms which further degrade and eat away
the permafrost coastline. The shoreline doesn’t stand a chance against higher
sea level and big waves, not to mention the communities built on a crumbling
permafrost foundation.

Shishmaref is just one example but it’s not the
only one. Residents of Shishmaref, and the nearby town of Kivalina, are trying to gather the funding to
dismantle these communities and move them to more solid ground. But this comes
with a steep price tag. The cost of moving Shishmaref has been estimated at
$100 million - more than $100,000 per resident. Right now, residents are
spending all of their energy on preserving their traditions and moving their
people to safer ground. In only 15 years, the Spruce Bark Beetle killed more
trees in Alaska
than any other North American insect.

Warming increases extreme events: This summer set new
temperature records in Alaska.
June 2004 was the warmest June in recorded history, coming in more than 5°
Fahrenheit above the 1971- 2000 average. While it may be tempting to just blame
this on global warming, it would be incorrect. Extreme weather happens with or
without global warming. What global warming does is increase the odds of seeing
extreme events like the record heat in Alaska
this summer.

You might think warmer temperatures would be
beneficial for the large tracts of
forests that cover much of southern Alaska.
But, in fact, Alaska’s
forests are hurting. A long run of warmer temperatures has paved the way for a
small beetle to devastate these beautiful forests. The spruce bark beetle,
which lives in and feeds on trees that drape the Kenai Peninsula, has killed
more trees in Alaska over the past 15 years than any other insect in North
American history.

The beetles need 60° Fahrenheit temperatures to
successfully fly from one tree to the next. That’s why the cool, damp weather
that used to blanket the Kenai Peninsula won’t
let a bark beetle infestation to last very long. And if that doesn’t work, a
hard, cold spring will kill off an infestation. Young trees protected
themselves by producing enough sap to drive out this parasite. But that’s all
changed.

The trees are no match for the spruce bark beetle
and the resulting number of casualties has been high: roughly 4 million acres
of spruce trees in southern Alaska
are gone. Throughout the 1990s, as Alaska
warmed and the hard springs didn’t appear, the bark beetles were unstoppable.
They managed to thrive on a string of abnormally warm winters in southern Alaska since 1987.

The only reason the bark beetles are contained now
is that they’ve literally eaten themselves out of house and home; there simply
aren’t any trees left. And there are signs that Alaska’s
warming climate is allowing more pests to thrive, which may mean more
infestations for Alaska’s
virgin wilderness.

http://www.democrats.com/node/3508