Here's an interesting entry from Lawrence Solomon from his The Next City colum in the Financial Post (a section in the National Post newspaper). Another fact to consider in thinking about "global warming" is that precisely the same (small) amount of warming has been measured on other planets in our solar system (e.g., Mars) which supports the idea that fluctuations in the Sun's output are responsible.

Global cooling sign: Solar winds at 50-year-low

by Lawrence Solomon

FP Comment, September 28, 2008

In yet another sign that the Earth could be heading in to a period of global cooling, NASA reports that the solar wind is now at a 50-year low, the lowest that NASA has seen. This change in solar activity, which began to occur about a decade ago, coincides with the end of the climb in global temperatures that had been underway for decades.

"What we're seeing is a long term trend, a steady decrease in pressure that began sometime in the mid-1990s," explains Arik Posner, NASA's Ulysses Program Scientist in Washington DC.

"How unusual is this event?

"It's hard to say. We've only been monitoring solar wind since the early years of the Space Age – from the early 60s to the present. Over that period of time, it's unique. How the event stands out over centuries or millennia, however, is anybody's guess. We don't have data going back that far."

As a result of the diminished solar wind, cosmic rays are entering the Earth's atmosphere in greater number. Research at the Danish National Space Institute shows that cosmic rays increase cloud cover on Earth, and that this cloud cover can have a cooling effect. Does this help explain why global temperatures plateaued a decade ago, and why they are now decreasing? Stay tuned!