Baby penguins are starving, and climate
change is to blame. But not in the way you might think.
Antarctic icebergs called B-15A and C-16 are about 54 miles and 34 miles long,
respectively. They calved from the Ross Ice Shelf in March 2000, and have
drifted northeast. The mammoth icebergs, along with increased sea ice, now
block open water in McMurdo Sound. The Adelie and Emperor penguins, which
usually swim beyond the open sound for food for their chicks, are stuck walking
across the ice dam. Without ready access to food, the chicks die. Several
of the smaller colonies, according to a National Science Foundation researcher,
will be obliterated.
Meanwhile, the Polar Bird, a supply ship for the Antarctic research stations,
has been jammed in the ice floes for over a month. For the Christmas holidays,
the people aboard departed for home by rescue helicopter. The icebreaker Aurora
Australis has chipped through to the Polar Bird, where they now are moored
together for the twenty-mile breakout to open water.
Around the Antarctic Peninsula from McMurdo Sound, the British Antarctic Survey
ship, Ernest Shackleton, has been unable to breach 200 miles of ice to reach
port in Halley Bay.
What's causing all the extensive sea-ice and iceberg conditions in the Antarctic?
After all, global warming from the increase in the air's carbon dioxide content
owing to human industrialization, are supposed to melt the ice. The 2001 report
from the United Nations Intergovernmental Panel on Climate Change (UN IPCC)
summarizes the forecasts from climate simulations when the concentration of
carbon dioxide increases in the air. The computer results unanimously predict
that the Antarctic should warm faster than the global average rate.
The alarm sounded in December when British Antarctic Survey researchers announced
that the temperature of the Antarctic Peninsula increased about five times
faster than the global average over the last fifty years. Is the Antarctic
Peninsula temperature rise the harbinger of man-made global warming?
But the Peninsula is a tiny portion (about 4%) of Antarctica. Now, just a
month later, University of Illinois researchers and colleagues report in Nature
on temperature records in Antarctica covering a broader area than the Peninsula.
The measurements show "a
net cooling on the Antarctic continent between 1966 and 2000..."
Some regions, like the McMurdo Dry Valleys, the largest ice-free area of the
continent, have cooled by 2 degrees C per decade in autumn, and 1.2 degrees
C per decade in summer from 1986 to 1999. The 2001 UN report concurs: "A
few areas of the globe have not warmed in recent decades, mainly over some
parts of the Southern Hemisphere oceans and parts of Antarctica."
As the Nature researchers dryly note, "Continental
Antarctic cooling, especially the seasonality of cooling, poses challenges
to models of climate and ecosystem change."
How challenging are those measurements to the computer simulations of global
warming from the added carbon dioxide content of the air from human actions
like fossil fuel burning? Quite.
According to the 2001 UN IPCC report, "It is very likely that: nearly
all land areas will warm more rapidly than the global average, particularly
those at high latitudes in the cold season... (p. 585)." (The UN report
even defines the term "very likely" as 90-99% chance that the result
is accurate, despite the fact that no computer simulation of climate yields
validated results, but that is another story.) The forecasts from the computer
simulations are unanimous: they expect strong warming trends averaged across
Antarctica in the case of human-produced global warming, stronger trends than
for the global average warming.
How to explain, then, the warming on some sites of the Antarctic Peninsula?
The southern ocean is a suspected major influence there. Decade-to-decade
shifts occur in the currents of the southern Pacific Ocean and the overlying
patterns of air circulation. Recent warming of the Peninsula owes to the present,
sustained configuration of those air and sea currents.
By the way, the decadal patterns of the Southern Hemisphere air and ocean
have been observed to vary naturally in the past, in periods before the air's
carbon dioxide content rose significantly. Thus, the shifts are not likely
pinned to man-made causes.
The cold trends have affected the Antarctic ecosystem. Both plant productivity
and the population of worms in the soil have diminished with the cooling trend.
The growth in sea ice has shifted the distribution of penguin colonies, some
of which are disappearing while others are growing.
Continent-wide, though, the Antarctic is cooling, and the penguins trapped
by vast sea ice extensions, along with other ecosystem changes, result from
the cooling. The chilling fact is that the cooling trend across Antarctica
over the last several decades contradicts the computer simulations of significant,
catastrophic man-made global warming.
This article was taken
from TechCentralStation website.
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