BBC NEWS | Science/Nature | Why the Sun seems to be 'dimming'
Here's the thesis:
1. Particulate matter (soot, etc) is changing cloud behavior much more than we'd thought. This results in increasing the earth's albedo (reflectivity -- so can satellites we see the moon brightening over the past few years? probably no baseline ...) and cooling the earth.
2. Changes in clouds are altering rainfall, may have been responsible for recent African droughts, and may cause drought in China.
3. The earth is not getting cooler, however. It's getting warmer. But, from #1, there's less sunlight reaching the earth. SOOO ... the greenhouse effect is much stronger than we though. That means the extreme global warming models are more plausible.
4. We're reducing particulate pollution even as we increase greenhouse gas pollution. That means less of #1 and #2, but it means much more of #3.
We'll see. Sounds like this thesis is only now gathering steam. It may yet be shot down. If it isn't ...