Amazon fires – photo: © Greenpeace

Thanks to a certain lipstick pitbull, the long-running debate about whether we are responsible for climate change has been given some high-profile coverage recently.

But while Sarah Palin wowed the Republicans in Minnesota, scientists have been quietly getting on with research into the effects of pollution on our weather.

One small piece of research into that complex relationship apparently shows how smoke from fires set to clear farmland in the Amazon in the dry season could either prevent clouds from forming, or accelerate cloud formation.

The outcome depends partly on the amount of aerosols – soot and tiny particles produced by burning coal, oil and vegetation. It also depends on how cloudy the skies are to begin with, and cloud height.

Ironically, either outcome can reduce rainfall: The aerosols can warm and dry out the air, or they can spawn so many cloud droplets that they exhaust available moisture before droplets can grow heavy enough to fall as rain.

You can read more about the research in the journal Science.