There is another DaVinci code. When they figure that out we may have a handle on how to handle global warming.
Reports in the late 1980s found the amount of sunlight reaching the planet’s
surface had declined by 4 to 6 percent since 1960. Suddenly, around 1990, that
appears to have reversed….Thing is, nobody knows what caused the apparent shift. Could be changes in cloud cover, they say, or maybe reduced effects of volcanic activity, or a reduction in pollutants.
[Could a reduction of pollutants actually increase warming? Hmmm.]
The percentage of sunlight reflected back into space by Earth is called albedo. The planet’s albedo, around 30 percent, is governed by cloud cover and the quantity of atmospheric particles called aerosols.
Amazingly, one of the best techniques for measuring Earth’s albedo is to watch the Moon, which acts like a giant mirror. Sunlight that reflects of Earth in turn reflects off the Moon and can be measured from here. The phenomenon, called earthshine, was first noted by Leonardo da Vinci. Albedo is a crucial factor in any climate change equation. But it is one of Earth’s least-understood properties, says Robert Charlson, a University of Washington atmospheric scientist. “If we don’t understand the albedo-related effects,” Charlson said …, “then we can’t understand the effects of greenhouse gases.”