Much to their surprise, scientists have found that less sunlight has been reaching the earth's surface in recent decades. The sun isn't going dark; rather clouds, air pollution and aerosols are getting in the way. Researchers are learning that the phenomenon can interact with global warming in ways that had not been appreciated.
"This is something that people haven't been aware of," says Shabtai Cohen of the Institute of Soil, Water and Environmental Sciences in Bet Dagan, Israel. "And it's taken a long time to gain supporters in the scientific world." Cohen's colleague Gerald Stanhill first published his solar dimming results 15 years ago.