Aerosols now cool

Apparently, according to the Guardian:

"Because (aerosol) particles are so light, they remain aloft for long periods, where they cool the Earth by reflecting radiation from the sun back out to space. Higher levels of aerosols lead to the formation of brighter clouds made up of smaller water droplets, which reflect still more of the sun's warming radiation. Cutting down on aerosols by improving air quality means that the Earth will in future be less shielded against the sun's rays.

Writing in the journal Nature today, scientists at the Meteorological Office and the US government's National Oceanic and Atmospheric Administration report that climate models used to predict future global warming have badly underestimated the cooling effect of aerosols."

It's all so confusing; I wish they'd make up their minds...