from: "Roger Coe" <rogercoe804atXYZxyznternet.com>
subject: Global temperature data
to: "Phil Jones" <p.jonesatXYZxyz.ac.uk>
Since we last corresponded it has become clear that 2007 will be another year in which the
global temperature has not risen
significantly, the 6th year on the HadCRUT3 data series. During this period the atmospheric
CO2 level has continued to rise
steadily at 1.9ppm/year and, according to Hansen, sulphate aerosols have declined equally
steadily thus reducing global dimming.
The period has therefore been relatively quiet in atmospheric terms except for the solar
insolation which has declined coincidentally
by the full solar cycle 23.
The paper by Camp and Tsung in GRL July 2007 analyses the last four 11 year cycles and
obtains a global warming signal of
almost 0.2K for each cycle. Similarly Scafetta and West in JGR November 2007 identify a
scenario in which the Sun might have
contributed up to 50% of the observed global warming since 1900. These and other papers
suggest that IPCC figure of about
8% solar contribution is a significant under estimate of a factor which could go a long way
to explaining the static global temperature data. It is surely important to try to get this
science right in view of the current emphasis on CO2 mitigation policies.