In spite of the hub-bub about greenhouse gas linked warming, there are a number of scientists who are convinced that solar activity is a much larger factor. [Some scientists even suggest carbon levels rise after the earth heats up as a consequence, not before/as a cause.] Sunspots are one measure of solar activity, and there is a roughly 11 year cycle in sunspots, as well as some longer ones that we have not nailed down exactly. The current sunspot cycle is delayed, and it's possible this is linked to the bout of cooler weather we are experiencing.
There are scientists who are raising questions about the longer term solar cycle, suggesting that perhaps we are in for a lull in sunspots, and a bout of long term cooler weather. Some have pointed to the example of the Maunder minimum, which was a long period with little sunspot activity where the earth cooled fairly dramatically for those living through it.
While it's too early to draw conclusions, I'm keeping an eye on this story and on the sun's sunspot activity at Spaceweather. According to NASA, it should be picking up this fall. Note that longer than average cycles (above 11 years) are apparently associated with short periods of cooling. I also note that today we have a sunspot appearing, after a lull.
If you really want to go out on a limb, there are some (I think Charles Nenner, though I could be mistaken) who link sunspots with general human activity, and further stock market performance, I'd assume due to some geo-magnetic connection. A new sunspot perks up and it looks like the primary bull market in the investing world (commodities) might be pulling out of it's tailspin. A connection? Who knows.
Yahoo: This year so far coolest for at least 5 years: WMO.
Maine Today: Brrr! Farmers' Almanac says cold winter ahead.
Milenio: Auguring brief era of ice in 2010.
An expert from the National Autonomous University of Mexico predicted that in about ten years the Earth will enter a "little ice age" which will last from 60 to 80 years and may be caused by the decrease in solar activity.
I have more on this topic here, here, and here.
Note: This blog is distributed through some media that doesn't handle links properly, therefore I will list the link address also for people to cut and paste if they wish.