How does rising atmospheric CO2 affect marine organisms?

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North Atlantic Storminess
Reference
Dawson, A.G., Elliott, L., Mayewski, P., Lockett, P., Noone, S., Hickey, K., Holt, T., Wadhams, P. and Foster, I.  2003.  Late-Holocene North Atlantic climate "seesaws", storminess changes and Greenland ice sheet (GISP2) palaeoclimates.  The Holocene 13: 381-392.

Background
Climate alarmists typically claim that warmer weather increases the frequency and intensity of various types of storms. The study that prompted this review investigated this premise for a real-world analogue of the current Modern Warm Period that may have been even warmer than the world of today, i.e., the Medieval Warm Period (MWP) of a thousand years ago.

What was done
The authors developed and analyzed relationships between temperature and storminess via Greenland ice-core ä18O data (which correlate with temperature) and Na+ (sea-salt) concentration data (which correlate with North Atlantic winter storminess) over the period AD 1000 to 1987.

What was learned
Dawson et al. report that "it is extremely rare to find any year during the last thousand when high Na+ concentrations coincided with extremely warm years," additionally noting that "the highest Na+ values are associated with years that were exceptionally cold."  They also report that "inspection of the data set for the MWP (here incorporating the time interval AD 1000-1400) indicates that there were very few winters during this period when high Na+ concentrations are recorded."  However, "as Mayewski et al. (1993) demonstrated," according to Dawson et al., "storm frequencies increased markedly after AD 1400."

What it means
During both short-term and longer-term warmth, as represented by individual warm years and multi-century warmth, respectively, North Atlantic winter storminess has typically been significantly suppressed.  Hence, there is every reason to believe that if the earth warms any further during the Modern Warm Period in which we currently reside, we can probably expect even less storminess than what is typical of the present, especially over the North Atlantic Ocean in winter, but probably elsewhere and at other times as well [see, for example, the various subheadings under Weather Extremes (Storms) in our Subject Index].

Reference
Mayewski, P.A., Meeker, L.D., Morrison, M.C., Twickler, M.S., Whitlow, S., Ferland, K.K., Meese, D.A., Legrand, M.R. and Steffenson, J.P.  1993.  Greenland ice core 'signal' characteristics: an expanded view of climate change.  Journal of Geophysical Research 98: 12,839-12,847.


Reviewed 20 October 2004