So what has really
changed? The data has been adjusted better this time around?
Antarctica is presently at maximum ice extent or pulse.
Of course the Northern
hemisphere remains half a degree warmer and this allows a blanket
loss of ice. Could someone explain just what part of Greenland is
presently losing more ice than snow is adding and the reverse? How
far has this boundary retreated?
Historically, these warm
periods usually are good for a couple of decades at least before they
reverse. Since it has become clear that CO2 is not a driver, it
remains to the historical record to inform us.
What would really ruin my
day is to see an abrupt return to conditions of two centuries ago.
Polar Ice Loss Increased
‘Five-Fold’ in 20 Years
Researchers say study is most
accurate to date
Over the past two
decades, ice melting in Greenland and Antarctica caused an
11-millimeter rise in the world’s sea levels, according to a new
study compiled by researchers who say it is the most accurate
measurement of ice loss to date.
“Both ice sheets
appear to be losing more ice now than 20 years ago, but the pace
of ice loss from Greenland is extraordinary, with nearly a fivefold
increase since the mid-1990s,” stated Erik Ivins of
NASA’s Jet Propulsion Laboratory, who helped lead the study. “In
contrast, the overall loss of ice in Antarctica has remained fairly
constant, with the data suggesting a 50 percent increase in
Antarctic ice loss during the last decade.”[
? - arclein]
Published in the
journal Science on Thursday, led by scientists at the University
of Leeds, and involving 47 researchers, the study used aircraft
and 10 different satellites to measure the ice and its rate of melt.
The research was backed by the European Space Agency and NASA.
The 11.1-millimeter,
or 0.47-inch rise in sea levels from the polar ice sheets makes up a
fifth of the total rise over the survey period. The remaining sea
level rise was caused by ice melt in other places, such as glaciers
and ice caps, the expansion of the warming oceans, and by groundwater
mining, according to the release.
The overall rate of
melting of the ice sheets in both Greenland and Antarctica has
increased over time. They are now shedding more than three times as
much ice—contributing to 0.95 mm rise in sea level per year—than
in the 1990s, when both were losing the equivalent of 0.27 mm per
year.
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Together, the two areas lose around 344 billion tons of ice
each year, researchers estimate, and of that, Greenland’s share is
around 263 billion tons, which was about what they expected. The
remainder was lost in Antarctica.
In previous years,
there was a disagreement about the amount of ice lost, especially
in Antarctica. Some studies showed massive ice loss and others even
showed a gain in ice.
In this latest study,
researchers were able to “reconcile the differences” among
numerous previous studies on the matter, a release from Leeds
University states.
One of the issues with
measuring ice loss is the remoteness of the locations—Greenland is
mostly uninhabited and Antarctica is entirely uninhabited, save a few
scientists—and the massive size of the ice sheets. Scientists also
have to differentiate between snow and ice.
The scientists said
the newest study’s data is consistent with climate change
predictions laid out in the 2007 Intergovernmental Panel on Climate
Change. However, the latest data offers clarity that the 2007 study
did not.
“Without these
efforts, we would not be in a position to tell people with confidence
how Earth’s ice sheets have changed, and to end the uncertainty
that has existed for many years,” said professor Andrew Shepherd,
head of the study.
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