How does rising atmospheric CO2 affect marine organisms?

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A Five-Century Rainfall Record for the Canadian High Arctic
Reference
Lamoureux, S.  2000.  Five centuries of interannual sediment yield and rainfall-induced erosion in the Canadian High Arctic recorded in lacustrine varves.  Water Resources Research 36: 309-318.

What was done
The author analyzed varved lake sediments obtained from Nicolay Lake, Cornwall Island, Nunavut, Canada.  Results were compared with rainfall events recorded at a nearby weather station over the period 1948-1978.  This comparison allowed the author to reconstruct a rainfall history for this location over the 487-year period from 1500 to 1987.

What was learned
The data were suggestive of a small, but statistically insignificant, increase in rainfall over the course of the record.  Heavy rainfall was most frequent during the 17th and 19th centuries, which were the coldest periods of the past 400 years in the Canadian High Arctic, as well as the Arctic as a whole.  In addition, says the author, "more frequent extremes and increased variance in yield occurred during the 17th and 19th centuries, likely due to increased occurrences of cool, wet synoptic types during the coldest periods of the Little Ice Age."

What it means
This study, like many others, contradicts the story promulgated by climate alarmists relative to the effects of global warming on extreme weather events and weather variability, both of which are typically claimed to increase with an increase in air temperature.  Here, however, in a part of the planet predicted to be most impacted by CO2-induced global warming - the Canadian High Arctic - a warming of the climate is demonstrated to reduce weather extremes related to precipitation, even in the face of a slight precipitation increase associated with the long-term warming.


Reviewed 4 October 2000