Suns Behaving Badly
I've mentioned before that there is some question about whether solar cycle changes might explain some, most, or even all of the supposed global warming. As a direct effect, no, but one theory is that changes in solar output affect cosmic ray flux, which influences cloud formation-and so an indirect effect. (Look up the history of how cloud chambers were used for analyzing output from atom smashers.) This might explain the apparent warming on Mars and Neptune roughly coincident with Earth warming in recent years.
Over at Watts Up With That? there is a chart showing changes in solar geomagnetic activity that somewhat fits with the cooling that has apparently been underway the last few years.
Cold weather would seem to fit this change in behavior. That it was 9 degrees Fahrenheit when I drove down the mailbox this morning at 10:30 AM is, of course, just coincidence!