...and fine-tune it.
Apparently, it's been know for awhile now that airborne bacterial streams could prompt precipitation in the form of rain or snow. The single-celled bodies which make up these streams serve as "nucleators" that water vapor can coalesce and freeze around. However, how ubiquitous these streams were, and how important they might be to cloud formation, has only recently become apparent:
"Atmospheric scientists haven't previously recognized that these particles are so widely distributed," [Louisiana State University microbiologist Brent Christner] said.
The findings raise the question of how climate change and human activities will affect bacterial balances in the sky. More immediately, they're a starting point for research on bacterial contributions to cloud formation and precipitation.
Since the impact of feedback loops involving clouds on global weather patterns is the largest source of uncertainty in current predictions of climate change, the new research should eventually allow for greater precision in these forecasts.
More cool cloud stuff here.