  It has been claimed by others that observed temporal correlations of
terrestrial cloud cover with `the cosmic ray intensity' are causal. The
possibility arises, therefore, of a connection between cosmic rays and Global
Warming. If true, the implications would be very great. We have examined this
claim to look for evidence to corroborate it. So far we have not found any and
so our tentative conclusions are to doubt it. Such correlations as appear are
more likely to be due to the small variations in solar irradiance, which, of
course, correlate with cosmic rays. We estimate that less than 15% of the
11-year cycle warming variations are due to cosmic rays and less than 2% of the
warming over the last 35 years is due to this cause.
