Scientists find evidence of "rain-making" bacteria

These biological particles could factor heavily into the precipitation cycle, affecting climate, agricultural productivity and even global warming. The new findings is published in the journal Science on Friday.

The research team examined precipitation from global locations and demonstrated that the most active ice nuclei -- a substrate that enhances the formation of ice -- are biological in origin. This is important because the formation of ice in clouds is required for snow and most rainfall.

Researchers have found biological ice nuclei in precipitation samples from Antarctica to Louisiana -- they`re ubiquitous.

Dust and soot particles can serve as ice nuclei, but biological ice nuclei are capable of catalyzing freezing at much warmer temperatures.

The concept of rain-making bacteria isn`t far-fetched. Many ski resorts use a commercially available freeze-dried preparation of ice-nucleating bacteria to make snow when the temperature is just a few degrees below freezing.

What makes this research more complicated is that most known ice-nucleating bacteria are plant pathogens. These pathogens, which are basically germs, can cause freezing injury in plants, resulting in devastating economic effects on agricultural crop yields.

"As is often ...