Potential Sources Of 'Rain-Making' Bacteria In The Atmosphere Identified

Brent Christner, assistant professor of biological sciences at LSU, recently found evidence that bacteria and biological cells are the most efficient ice-forming catalysts in precipitation from locations around the globe. The formation of ice in clouds is important in the processes that lead to snow and rain. Ice-nucleating bacteria – which have been referred to as "rain-making bacteria" – may be significant triggers of freezing in clouds and influence the water cycle.

http://www.sciencedaily.com/releases/2008/11/081119171523.htm