Nature has a review on its front cover (subs req, of course) that pretty well says forget solar forcing for explaining current climate change (“brightening of the Sun is unlikely to have had a significant influence on global warming since the seventeenth century”; not to be outdone, Science refers to a Earth Planet. Sci. Lett. peice saying much the same). But inside we have Climate change: A cosmic connection about CLOUD, which is a CERN expt to try to find the elusive cosmic-ray cloud connection that much of the solar folk hope for by shooting particle beams through controlled air. This idea has been around quite a while – at least since the EGU was last at Nice, and probably before. But it looks like its finally been funded ($11 M for the first phase; not obviously a useful use of money).
The problem with the cosmic-ray connections stuff is twofold: they keep changing their minds about how it is supposed to work (high clouds? total? low? where… etc In a 2004 article published in Eos, Paul Damon… and Peter Laut… discussed several examples of what they called “unacceptable handling of observational data” by Svensmark and Friis-Christensen which exaggerated the correlation. Among several flaws, including arithmetical errors, they noted that the cloud data that had been used originally did not represent total global cloud cover, and that when the correct data were used the correlation broke down. Svensmark began to use a different measure of cloudiness, justifying this by arguing that the new measure made more sense than the original one as something that the cosmic rays might be influencing.) and the mechanism is quite unclear (well in many cases there is no mechanism: its just correlations. But many cloud folk seem to think there is no chance of cosmic rays making the required changes to clouds). This expt presumably might shed some light on the mechanism, errr, or maybe it won’t.
Yet more evidence that people challenging the dominant paradigm of GW can’t get funding :-)