[extropy-chat] Ice cores show warming 'natural' (or not)
spike66 at comcast.net
Sat Jan 7 06:54:09 UTC 2006
Damien has posted two interesting articles. This showed
up today in the MSM claiming that the warming is happening
faster at the poles than in the tropics. This just doesn't
make sense. Good news indeed if true, but I don't see
how it could be. spike
2005 Ties for 2nd Warmest Year Ever, But Cause Still Uncertain
Friday, January 06, 2006
By Robert Roy Britt
A new study finds last year tied for the second-warmest year since reliable
records have been kept starting in the late 1800s.
The global average temperature in 2005 was 0.54 degrees Fahrenheit (0.3
Celsius) warmer than the long-term average, tying a mark set in 2002.
But a puzzling general pattern, seen the past three decades, persisted: The
most significant warming occurred in the Arctic, where the ice cap is
shrinking at an alarming pace.
Seven times faster
Since November 1978, the Arctic atmosphere has warmed seven times faster
than the average warming trend over the southern two-thirds of the globe,
based on data from NOAA satellites.
"It just doesn't look like global warming is very global," said John
Christy, director of the Earth System Science Center at the University of
Alabama in Huntsville.
The warmest five years since the 1890s, when reliable record-keeping began:
2. 2002 (tie)
Scientists agree the planet is warming. Ground in the Northern Hemisphere
that's been frozen since the last Ice Age is melting and collapsing.
But they are still debating exactly how much and to what extent humans are
contributing by burning fossil fuels that create greenhouse gases.
Lack of understanding
In a report last May, researchers said they know very little about how Earth
absorbs and reflects sunlight, crucial factors that control climate. Other
studies have indicated that increased output from the Sun is responsible for
more of global warming than was previously realized.
"Obviously some part of the warming we've observed in the atmosphere over
the past 27 years is due to enhanced greenhouse gases. Simple physics tells
you that," Christy said. "But even if you acknowledge the effects of
greenhouse gases, when you look at this pattern of warming, you have to say
there must also be something else at work here."
Nobody's sure what that might be.
"The carbon dioxide from fossil fuels is distributed pretty evenly around
the globe and not concentrated in the Arctic, so it doesn't look like we can
blame greenhouse gases for the overwhelming bulk of the Northern Hemisphere
warming over the past 27 years," Christy said. "The most likely suspect for
that is a natural climate change or cycle that we didn't expect or just
Opposite of expectations
Over the past 27 years, since the first temperature-sensing satellite was
launched, the overall global temperature has risen 0.63 degrees Fahrenheit,
while the hike in the Arctic has been 2.1 degrees.
"The computer models consistently predict that global warming due to
increasing greenhouse gases should show up as strong warming in the
tropics," Christy said.
Yet the tropical atmosphere has warmed by only about 0.3 degrees Fahrenheit
in 27 years.
A study last year examined natural climate change going back more than 1,000
years. How do the recent changes stack up?
"It would be fairly rare to have this much warming all from natural causes,
but it has happened [in the past]," Christy said. "What we've seen isn't
outside the realm of natural climate change."
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