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27 Sep 07 - USC College researcher shows that deep-sea temperatures rose
1,300 years before the buildup of atmospheric carbon dioxide, ruling out
CO2 as driver of the last ice age’s meltdown.
In contrast to what is often inferred from the geologic record,
carbon dioxide did not cause the end of the last ice age, a new USC
study published in Science suggests.
"There has been this continual reference to the correspondence
between CO2 and climate change as reflected in ice core records as
justification for the role of CO2 in climate change," said
paleoclimatologist Lowell Stott, the study’s lead author and a
professor of earth sciences at USC College.
"You can no longer argue that CO2 alone caused the end of the
ice ages."
Deep-sea temperatures warmed about 1,300 years before the tropical
surface ocean and well before the rise in atmospheric CO2, the study
found. The finding suggests the rise in greenhouse gas was likely a
result of warming – but not its main cause.
(Rising
CO2 levels are a result of warming, not a cause
-
just as I say in "Not by Fire but by Ice.")
"What this means is that a lot of energy went into the ocean long
before the rise in atmospheric CO2," Stott said.
But where did this energy come from? Evidence pointed southward.
The warming deep water appeared to come from the Antarctic Ocean, then
moved northward, the scientists wrote
In addition, the researchers noted that the increases in deep-sea
temperature coincided with the retreat of Antarctic sea ice, both
occurring 19,000 years ago, before the northern hemisphere’s ice
retreat began.
Finally, Stott and colleagues found a correlation between melting
Antarctic sea ice and increased springtime solar radiation over
Antarctica, suggesting this was the energy source.
As the sun pumped in heat, the warming accelerated because of sea-ice
albedo feedbacks, in which retreating ice exposes more of the ocean that
can absorb heat from the sun, much like a dark T-shirt on a hot day, and
this results in more melting.
In addition, the authors’ model showed how changed ocean conditions
may have been responsible for the release of CO2 from the ocean into the
atmosphere, which like the albedo feedbacks, also accelerated the
warming.
(I
also say this in "Not by Fire but by Ice" – that
rising CO2 levels come from the warming ocean.)
The link between the sun and ice age cycles is not new. The theory of
Milankovitch cycles states that periodic changes in Earth’s orbit
cause increased summertime solar radiation in the northern hemisphere,
which controls ice size.
If CO2 caused the warming, one would expect surface temperatures to
increase before deep-sea temperatures, since the heat slowly would
spread from top to bottom. Instead, carbon-dating showed that the water
used by the bottom-dwelling organisms began warming about 1,300 years
before the water used by surface-dwelling ones, suggesting that the
warming spread bottom-up instead.
(Just as I say in "Not by Fire but by Ice." It’s not
global warming, it’s ocean warming. And this time
it’s
leading us into an ice age.)
Stott is an expert in paleoclimatology and was a reviewer for the
Intergovernmental Panel on Climate Change. He also recently co-authored
a paper in Geophysical Research Letters tracing a 900-year
history of monsoon variability in India.
See entire article by Terah U. DeJong:
http://www.usc.edu/uscnews/stories/14288.html
Thanks to Vagrant Viking for this link
See also:
http://www.sciencedaily.com/releases/2007/09/070927154905.htm
Thanks to Jimmy Walter for this link
See also:
http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=57895
Thanks to Craig Adkins for this link
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