Why the Sun seems to be 'dimming'

We are all seeing rather less of the Sun, according to scientists who have been looking at five decades of sunlight measurements.
They have reached the disturbing conclusion that the amount of solar energy reaching the Earth's surface has been gradually falling.
Paradoxically, the decline in sunlight may mean that global warming is a far greater threat to society than previously thought.
The effect was first spotted by Gerry Stanhill, an English scientist working in Israel