Nova’s Dimming the Sun appeared this week on PBS. Though Jon Stewart attributes less sunshine over the last several years to Dick Cheney, pollution is actually to blame for up to 22% less sunshine in places all around the world (including the U.S.). According to the program, the fact that earth has received and continues to receive less light means temperatures are lower than they would be if ray-blocking particle pollution suddenly ended.
Researchers used data gathered on September 11, 2001 and the days that followed when air traffic came to a virtual halt in America. Findings show that temperatures were dramatically warmer during the day and cooler at night. Other studies also validate the work, but 911 provided a unique opportunity.
If you get the chance, the program is worth watching.