How does rising atmospheric CO2 affect marine organisms?

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Cosmic Rays and Climate Change
Kniveton, D.R. and Todd, M.C.  2001.  On the relationship of cosmic ray flux and precipitation.  Geophysical Research Letters 28: 1527-1530.

What was done
Previous work has suggested that increased (decreased) cosmic ray flux at the solar minimum (maximum) causes increased (decreased) ice-nucleation,
precipitation efficiency and precipitation at high geomagnetic latitudes and decreased (increased) ice-nucleation, precipitation efficiency and precipitation at low geomagnetic latitudes.  Using cosmic ray data recorded by ground based neutron monitors, global precipitation data from the Climate Predictions Center Merged Analysis of Precipitation (CMAP) project, and estimates of monthly global moisture from the National Centers for Environmental Prediction (NCEP) reanalysis project, the authors set out to evaluate whether there is any empirical evidence to support the hypothesis that solar variability (represented by changes in cosmic ray flux) is linked to climate change (manifested by changes in precipitation and precipitation efficiency) over the period 1979-1999.

What was learned
The authors report there is "evidence of a statistically strong relationship between cosmic ray flux (CFR), precipitation (P) and precipitation efficiency (PE) over ocean surfaces at mid to high latitudes," as variations in both precipitation and precipitation efficiency for mid to high latitudes showed a close relationship in both phase and magnitude with variations in cosmic ray flux, varying 7-9% during the solar cycle of the 1980s.  Other potential factors that might explain the trends in precipitation and precipitation efficiency were ruled out due to poorer statistical relationships.

What it means
This study suggests that small changes in solar output can induce significant changes in earth's climate.  With empirical evidence mounting for a solar-induced cloud and water vapor climate feedback (see Solar Climate Effects and
Extraterrestrial Climate Effects in our Subject Index), and given the fact that the total magnetic flux leaving the sun has risen by a factor of 1.41 over the period 1964-1996 and by a factor of 2.3 since 1901 (see More Evidence for a Solar-Climate Link), climate modelers should be paying more attention to these phenomena and incorporating them into their general circulation models of the atmosphere; for it could be that much, if not all, of the 20th century warming had its origins in solar variability and not the historical rise in the air's CO2 concentration.