How does rising atmospheric CO2 affect marine organisms?

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Holocene Climate off the Coast of Nova Scotia
Reference
Levac, E.  2001.  High resolution Holocene palynological record from the Scotian Shelf.  Marine Micropaleontology 43: 179-197.

What was done
In the words of the authors, "the Holocene history of Canada's Atlantic region was examined using a high-resolution palynological record from the Scotian Shelf (La Have Basin)."

What was learned
Sea surface temperatures in February and August were up to 5°C warmer than those of today from approximately 10,500 to 8,500 years ago.  They then declined for about the next 2,000 years, after which August temperatures have generally remained similar to the August temperatures of today, while February temperatures have remained about 2°C warmer than today's normal.  Exceptions to these general conditions have occurred at approximate 1000-year intervals, when periods of significantly colder temperatures prevailed.  The last 500 years of the record (which ends about 100 years ago) then depicts a slight cooling of August temperatures.

What it means
Climate has changed significantly many times throughout the course of the last ten millennia in the area of Canada's Atlantic Provinces; and the vast majority of these changes have occurred independently of any changes in atmospheric CO2 concentration.  During this period, it has been both warmer and colder than it is now ... several times, in fact.  Hence, neither a future warming nor cooling would be anything unusual for this part of the globe.  Both things have happened before, and both will likely happen again, independent of anything man may or may not do, including the continued burning of prodigious quantities of fossil fuels.


Reviewed 2 January 2002