There's now a summary of the current research findings on global dimming. That is essentially the measurement of the amount of solar radiationthat reaches the earth's surfacer at a given point. Highly relevant to weather, climate, temperatures. The findings are published in a special edition of the Journal of Geophysical Research. There are indications that less and less solar radiation is hitting the earth due to aerosols and other additions to the atmosphere from human activity. One finding, the more diffuse sunlight now is more efficiently used by plants for photosynthesis meaning that more CO2 is being captured naturally. Is that enough to offset increasing CO2 emissions? In 2005 the BBC aired a still-controversial documentary on global dimming. If you google "global dimming BBC" you'll get over 100,000 listings, many are videos. Enough to keep you busy until the sun shines.