This Friday, Science published this paper first authored by Assistant Research Scientist Kaicun Wang with Shunlin Liang and Bob Dickinson of the University of Texas. The article can be found at: http://www.sciencemag.org/cgi/content/abstract/323/5920/1468 .

Its abstract reads:

" Visibility in the clear sky is reduced by the presence of aerosols,   whose types and concentrations have a large impact on the amount   of solar radiation that reaches Earth's surface. Here we establish   a global climatology of inverse visibilities over land from   1973 to 2007 and interpret it in terms of changes in aerosol   optical depth and the consequent impacts on incident solar radiation.   The aerosol contribution to "global dimming," first reported in   terms of strong decreases in measured incident solar radiation up to   the mid-1980s,> has monotonically increased over the period analyzed.   Since that time, visibility has increased over Europe, consistent   with reported European "brightening," but has decreased substantially   over south and east Asia, South America, Australia, and Africa,   resulting in net global dimming over land."

The atmospheric aerosols are small particles in the air, which reduce our visibility, the maximum distance at which an observer can discern the outline of an object against the horizon sky. This study supplies a long-term climatology of atmospheric aerosols using the meteorological visibility observations. Atmospheric aerosols affect our climate through its direct effect (reducing the solar radiation reaching the earth’s surface) and its indirect effects (interactions with clouds and precipitation). This study supplies a basic dataset on our climate change study.    

Their article has already been reported in the following outlets: Associated Press, Reuters, Nature, Bloomberg News, Australian AP, USA Today, Digital Journal, CanWest News Service, Financial Times and Health Central.