Now THIS is something new on the climate/ weather front!

Manly Harbour Storm October 2008

National Geographic’s website reports that a scientist claims to have found rain making bacteria. This is one of heaven knows how many factors that are not yet understood about climate, and therefore not built into computer climate models.

In Rainmaking bacteria ride clouds to “colonise” Earth, National Geographic describe microbiologist Brent Christner’s discovery.

Rainmaking bacteria that live in clouds may have evolved the ability to spur showers as a way to disperse themselves worldwide, a recent study found.

The research gives scientists a first glimpse into the link between biology and climate, and into how the tiny organisms globe-trot with the weather cycle.

 The microbes—called ice nucleators—are found in rain, snow, and hail throughout the world, according to previous work by Brent Christner, a microbiologist at Louisiana State University.

Christner had shown that, at a high enough concentration, these organisms may be efficient drivers for forming ice in clouds, the first step in forming snow and most rain.

But he hadn’t been able to pinpoint their source—until now.

In the recent study, Christner and colleagues found that the critters hail from snow, soils, and young plant seedlings in such such far-flung sources as Antarctica, Canada’s Yukon Territory, and the French Alps.

National Geographic report that this is a theory which may build upon earlier studies of “nucleators” – materials which trigger formation of ice crystals in clouds.

The theory—called bioprecipitation—was pioneered by David Sands, a plant pathologist at Montana State University, in the 1980s. But little information existed on how the rainmaking bacteria moved through the atmosphere until Christner and his colleagues began their work in 2005.

This also links into the urban legend that trees attract rain – it may well be fact!

The concept also ties into Sands’s ongoing study of the idea that drought cycles are connected to bacteria in clouds….

For instance, if people overgraze lands, “these bacteria are without a home … and can have serious consequences, possibly, for lack of rainfall,” Sands said.

Simply put, a lack of vegetation may lead to a lack of bacteria, which could limit clouds’ ability to shed rain.

Now this is really interesting! How do these bacteria work? How many are around at present? How many were around at different stages in the Earth’s climate history? Can our ice core and fossil experts identify these bacteria in their samples?

Could this help man to prevent or reverse dought? Does this affect weather or climate?

I hope to read more soon on this discovery.