What was done
Understanding the mechanisms behind cloud formation and cloud properties has long been a difficult task in global climate change studies.  In this paper, the authors focused on the potential for organic solutes to alter surface tension characteristics of cloud condensation nuclei and thereby influence cloud droplet formation and albedo.  Specifically, they studied the effects of real atmospheric solutes collected from cloud water (fog) in the Po Valley in Italy

What was learned
The effect of organic matter solutes on the formation and reflective properties of clouds was found to be significant, such that water vapor was more likely to form on organic solute-affected aerosols of lower surface tension, creating more and more highly-reflective cloud droplets.  In the words of the authors, "the error produced in ignoring this [cooling] effect is estimated to be comparable to other calculated direct and indirect influences of aerosols on scattering and absorption of solar radiation."

What it means
The authors note that the organic fractions and concentrations in the aerosols they studied "are similar to air in or downwind of other large agricultural/industrial regions."  Consequently, as the human population grows, and as agricultural/industrial enterprises grow with it, we should see the cooling effect discussed in this study grow in significance, which will tend to ameliorate future warming tendencies.