[Vision2020] NOAA Confirms Dramatic Sea Ice Loss

[Ted Moffett]

All-

The NOAA study I referenced focused on Arctic sea ice loss, which, while a
great environmental and ecosystem disaster, associated with problems caused
by global warming that are planetary wide, will not cause sea levels to
rise.  Most of the Arctic ice is floating on the ocean, so it is displacing
its weight in liquid water.  The main sources of ice melt that will cause
sea levels to rise dramatically are Greenland and Antarctica, where the ice
is on land above water.  The potential is for sea level rise of over 150
feet.  There are verified measurements that both Greenland and Antarctic ice
is threatening ocean level rise.  A skeptic might argue that snow fall will
replace the ice as fast as it melts, even assuming global warming is
occurring.  The increased atmospheric moisture caused by global warming will
cause an increase in snow fall over Greenland or Antarctica.  But with
profound global warming of, let's say, 5 C. average global temperatures, it
is very doubtful the melting could be offset by increasing snow fall.

The Arctic ice is melting extremely fast due to the effects of albedo (a
term for the reflectivity of a body of surface).  Ice or snow reflects a
large amount of solar radiation.  When it melts and exposes the ocean, as in
Arctic ice, the darker water absorbs more energy and stores it, increasing
the rate of the melting of ice.  A snow ball effect, no pun intended.  When
or if land areas on Greenland or Antarctica become more exposed as ice
melts, this will also increase albedo, accelerating the melting,
though perhaps not as fast as in the case of the Arctic ice over water.
Antarctica has already has massive ice sheets break apart on the edges of
this continent, sheets that have been stable for thousands of years,
increasing the rate of movement of glaciers that dump into the ocean,
exposing warmer water to the edges of Antarctica, increasing melt rate in
this area.

Some scientists think snow fall replacement in the interior of Antarctica is
increasing, helping to offset melting of glaciers on the edges.

Ted Moffett


On 9/10/07, Mark Solomon <msolomon at moscow.com> wrote:
>
> Hard to look on the bright side when rising sea levels caused by
> melting ice threaten millions of people in low lying areas of Asia,
> Europe, the US and the rest of the world.
>
> m.
>
> At 10:52 AM -0700 9/10/07, lfalen wrote:
> >Ted
> >Look on the bright side.  A complete opening of the Northwest
> >Passage would cut 2500 miles off of the journey from Europe to Asia.
> >Roger
> >-----Original message-----
> >From: "Ted Moffett" starbliss at gmail.com
> >Date: Fri, 07 Sep 2007 13:03:41 -0700
> >To: "MoscowVision 2020" vision2020 at moscow.com
> >Subject: [Vision2020] NOAA Confirms Dramatic Sea Ice Loss
> >
> >>  *NOAA researchers confirm predictions of dramatic sea ice loss *
> >>
> >>
> >>
> http://www.technewsworld.com/story/A0OHya0BOvEw9B/Study-Confirms-Shrinking-Levels-of-Arctic-Sea-Ice.xhtml
> >>
> >>  By DAN JOLING
> >>  Associated Press Writer
> >>
> >>  ANCHORAGE, Alaska (AP) -- Computer predictions of a dramatic decline
> of sea
> >>  ice in regions of the Arctic are confirmed by actual observations,
> according
> >>  to scientists for the National Oceanic and Atmospheric Administration.
> >>
> >>  The Seattle-based researchers reviewed 20 computer scenarios of the
> affects
> >>  of warming on sea ice used by the Intergovernmental Panel on Climate
> Change
> >>  in its assessment report released this year.
> >>
> >>  The researchers compared those models with sea ice observations from
> 1979
> >>  through 1999, rejecting about half because they did not match what
> >>  satellites showed, said oceanographer James Overland.
> >>
> >>  But using the most reliable models, the NOAA scientists reached the
> same
> >>  unhappy conclusion: by 2050, summer sea ice in the Beaufort Sea off
> Alaska's
> >>  north coast likely will have diminished by 40 percent compared to the
> 1980s.
> >>  The same is likely for the East Siberian-Chukchi Sea region off
> northwest
> >>  Alaska and Russia. In contrast, Canada's Baffin Bay and Labrador
> showed
> >>  little predicted change.
> >>
> >>  There was less confidence for winter ice, but the models also predict
> a sea
> >>  ice loss of more than 40 percent for the Bering Sea off Alaska's west
> coast,
> >>  the Sea of Okhotsk east of Siberia and the Barents Sea north of
> Norway.
> >>
> >>  A 40 percent loss of summer sea ice off Alaska in the Beaufort Sea
> could
> >>  have profound effects on marine mammals dependent on the sea ice such
> as
> >>  polar bears, now under consideration by the U.S. Fish and Wildlife
> Service
> >>  for "threatened" status under the Endangered Species Act because of
> changes
> >>  in the animals' habitat from global warming.
> >>
> >>  Overland, an oceanographer at NOAA's Pacific Marine Environmental
> Laboratory
> >>  in Seattle, and Muyin Wang, a meteorologist at NOAA's Joint Institute
> for
> >>  the Study of the Atmosphere and Ocean at the University of Washington
> in
> >>  Seattle, reviewed 20 computer models provided through the IPCC. Their
> >>  research paper will be published Saturday in Geophysical Research
> Letters, a
> >>  publication of the American Geophysical Union.
> >>
> >>  In the 1980s, sea ice receded 30 to 50 miles each summer off the north
> coast
> >>  of Alaska, Overland said.
> >>
> >>  "Now we're talking about 300 to 500 miles north of Alaska," he said of
> >>  projections for 2050.
> >>
> >>  That's far past the edge of the highly productive waters over the
> relatively
> >>  shallow continental shelf off Alaska's north coast, considered
> important
> >>  habitat for polar bears and their main prey, ringed seals, plus other
> >>  ice-dependent mammals such as walrus.
> >>
> >>  Kassie Siegel of the Center for Biological Diversity, who wrote the
> petition
> >>  seeking federal protection for polar bears, said NOAA's retrospective
> of sea
> >>  ice projections does not even take into account sea ice figures for
> this
> >>  summer recorded by the National Snow and Ice Data Center. As of
> Tuesday, the
> >>  center's measurement of sea ice stood at 1.70 million square miles,
> far
> >>  below the previous record low for summer ice of 2.05 million square
> miles
> >>  recorded Sept. 20, 2005.
> >>
> >>  The situation is dire for polar bears, Siegel said.
> >  >
> >>  "They're going to drown, they're going to starve, they're going to
> resort to
> >>  cannibalism, they're going to become extinct," she said.
> >>
> >>  As ice recedes, many bears will get stuck on land in summer, where
> they have
> >>  virtually no sustainable food source, Siegel said. Some will try and
> fail to
> >>  swim to sea ice, she said. Bears that stay on sea ice will find water
> beyond
> >>  the continental shelf to be less productive. Females trying to den on
> land
> >>  in the fall will face a long swim.
> >>
> >>  "It's absolutely horrifying from the polar bear perspective," she
> said.
> >>
> >>  Less sea ice also will mean a changing ecosystem for commercial
> fishermen
> >>  and marine mammals in the Bering Sea, Overland said.
> >>
> >>  With sea ice present, much of the nutrients produced in the ocean feed
> >>  simple plankton that bloom and sink to the ocean floor, providing rich
> >>  habitat for crabs, clams and the mammals that feed off them, including
> gray
> >>  whales and walrus.
> >>
> >>  "If you don't have the ice around, the productivity stays up closer to
> the
> >>  surface of the ocean," Overland said. "You actually have a change in
> the
> >>  whole ecosystem from one that depends on the animals that live on the
> bottom
> >>  to one that depends on the animals that live in the water column. So
> you
> >>  have winners and losers."
> >>
> >>  That could mean short-term gains for salmon and pollock, he said. But
> it
> >>  also could mean that fishermen will have to travel farther north to
> fish in
> >>  Alaska's productive waters, and warm-water predators might move north.
> >>
> >>  Overland said sea ice computer models have performed well accounting
> for how
> >>  ice melts from global warming and for the albedo effect - accelerated
> >>  warming due to the presence of dark water that absorbs most of the
> sun's
> >>  radiation, warming the ocean and making it harder for water to freeze,
> in
> >>  contrast to ice, which reflects most of the sun's radiation.
> >>
> >>  The models do not do as well accounting for wind and cloud patterns
> and
> >>  other factors that may have contributed to recent warming, Overland
> said.
> >>
> >>  But the contribution to warming by greenhouse gas emissions likely are
> set,
> >>  he said. Emissions stay in the atmosphere for 40 to 50 years before
> being
> >>  absorbed by the ocean. The amount put out in the last 20 years and the
> >>  carbon dioxide put out in the next 20 will be around to influence the
> >>  half-century mark, Overland said.
> >>
> >>  "I'm afraid to say, a lot of the images we are going to see in the
> next 30
> >>  to 40 years are pretty much already established," he said.
> >>
> >>  ------
> >>
> >>  Vision2020 Post: Ted Moffett
> >>
> >>
>
>
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