Less pollution, more warming

Reduced air pollution and increased water evaporation appear to be adding to man-made global warming.

Research presented at a major European science meeting adds to other evidence that cleaner air is letting more solar energy through to the Earth's surface.

Other studies show that increased water vapour in the atmosphere is reinforcing the impact of man-made greenhouse gas emissions.

Scientists suggest both trends may push temperatures higher than believed.

Between the 1950s and 1980s, the amount of solar energy penetrating through the atmosphere to the Earth's surface appeared to be declining, by about 2% per decade.

This trend received some publicity under the term "global dimming".

"During the solar dimming we had really no temperature rise. And only when the solar dimming disappeared could we really see what is going on in terms of the greenhouse effect, and that is only starting in the 1980s."

Can't win, can we? Damned if we do and damned if we do.

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