Posted on 06/18/2004 7:28:25 PM PDT by dila813
Global Warming May Be Delayed By Increase In Ocean Silica Boston College scientist's 'silica hypothesis' addresses atmospheric CO2 decrease during ice ages and discusses implications for slowing the rise of atmospheric CO2 today
CHESTNUT HILL, MA (6-19-00) -- Increasing amounts of silica in the ocean may be removing large amounts of carbon dioxide from the atmosphere, slowing its overall build-up and delaying the onset of global warming. According to Boston College Geologist Kevin G. Harrison, writing in the June 2000 issue of Paleoceanography, an increase in ocean silica levels also could explain why atmospheric carbon dioxide levels decreased by 30 percent during glacial times, a significant change that has perplexed scientists for decades.
According to Harrison, human activity has doubled the amount of dust delivered to the oceans today. Until now, scientists have been unable to propose an elegant mechanism to link this increase in dust with decreasing atmospheric carbon dioxide. In Paleoceanography, Harrison proposes just such a mechanism: The Silica Hypothesis.
This hypothesis suggests that changing the supply of silica to the ocean may alter pCO2 levels. Some of the silica present in the dust dissolves and becomes available for biological uptake. In glacial times, the increased silica levels shifted species composition, changing the distribution of plankton species. Diatom populations increased and coccolith populations decreased. This shift increased the ability of the ocean to remove carbon dioxide from the atmosphere: decreasing the population of coccoliths decreased the flux of calcite to the sediments, which in turn lowered pCO2 levels.
Harrison's model estimates that a seven-fold increase in dustiness would have lowered carbon dioxide levels from 280 ppm to 200 ppm--enough to explain the observed glacial-interglacial pCO2 transition.
Organic biomarkers in the sedimentary record support Harrison's hypothesis.
Harrison notes that present-day increases in dust level suggest that the same diatom-based mechanism may be at work today, removing significant amounts of carbon dioxide from the atmosphere and slowing the rate of global warming.
For the full text of this article, entitled "Role of increased marine silica input on paleo-pCO 2 levels," see the June 2000 issue of Paleoceanography, (Vol. 15, No. 3, pp. 292-298).
Hey, what's going on at Boston College?
In light of being discredited, I think the "global warmers" are creating a "back door" for themselves on this.
Ahh.. Global Warming.
I still remember an 8th grade reading teacher back in the late 80s who told all of us that we were going to run out of oxygen because of the logging industry "destroying" the South American rain forests, and we needed to bring in money to "purchase" as many acres as possible.
No kidding.
We were supposed to run out of air by the year 2000. :).
ping
I always had that idea of creating a super-adhesive from barnacles...
oh for goodness sake!!
Can't we get anything done on time & under budget!! ;-)
We did; we've been running evaporated B.S. ever since.
I'd like to see you pry it from their sticky fingers.
But keep sending money.
(steely)
Hailing as I do from a day when folks openly worried about global cooling and the coming ice age I'm shocked. ;-)
Just the Democrats.
/john
Obviously this is being caused by massive numbers of AOL discs being leached out of landfills.
Thank goodness that your teacher was able to collect enough money to save us all.
Plus we were to have run out of oil, and the new ice age from the global cooling in the 70s was to have overtaken us.
Do these idiots ever stop to think how stupid they sound?
In the 60's and 70's when I was in school, we were being told of the coming Ice Age.
Global warming has been happening for 10,000 years, Thats what melted the glaciers.. still melting them too.. The oceans are full of silicone(sand) too. If the globe was'nt warming Kanuckistan would be Iceholeistan...
OK. "Global Warming" causes more deserts that results in more airborn dust that settles in the ocean preventing "Global Warming."
So mother earth takes care of itself, right?
How are the envirowhackos going to make the US pay for this?
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