"AEROSOLS AND CLIMATE - A HAZY FUTURE FOR THE BLUE PLANET?"
One of the most visible impacts of human activities is
the brownish haze that pervades many industrialized regions, as well as
rural areas in the tropics and the subtropics subject to biomass burning.
Well known examples are the Los Angeles Smog, the Arctic haze and the Asian
Brown Cloud. Long-range transport transforms this haze into a regional
and hemispherical scale aerosol layer which leads to large reductions in
the surface solar irradiance, a corresponding increase in atmospheric solar
heating, stronger low level inversions, suppression of rainfall,
and less efficient removal of pollutants. Have these tiny manmade
particles offset a substantial part of the global warming? Can they lead
to a weaker hydrological cycle which connects directly to water availability
and quality, a major environmental issue of the 21st century ? What
is the impact of the Asian Brown Cloud, potentially a major environmental
threat for this century? Modern satellite observations, field experiments
and models are finally beginning to unravel the impacts of these tiny particles.