Possible link between microorganisms and clouds sparks international debate

Stockholm researchers hit international headlines recently when news of their research was featured in acclaimed magazine New Scientist.

Professor Barbara Nozière, Department of Applied Environmental Science (ITM), Stockholm University

Professor Barbara Nozière at Stockholm University’s Department of Applied Environmental Science (ITM), in collaboration with colleagues from Stockholm University, the Swedish Agricultural University, and the University of Sao Paolo in Brazil, discovered that surfactants secreted by microorganisms like bacteria, fungi and micro-algae might trigger the formation of clouds in the atmosphere. 

“We gave a report at the annual meeting of the American Geophysical Union in San Francisco last month,” says Professor Nozière, and recent holder of the Marie Curie Chair. “A journalist picked up on our findings at the conference and the story made it to the New Scientist.”

The article, which has already prompted over twenty comments from readers mulling over the implications of the team’s research, clearly struck a chord. This article was also echoed by many other web sites reporting scientific news in English, Russian, Polish (see links) and journalists from as far afield as Canada have been in touch to discuss the research.

“It’s great to see academic research being taken up by the public,” enthused Nozière. “It’s important that what we do at the university touches people in the real world.”

The focus of the research was the cloud-forming efficiency of substances produced by microorganisms common to the oceans and surface of the earth. Aerosol samples were collected from different regions including the temperate forests of Finland and Sweden and the Amazonian forests of Brazil.

Strikingly, these substances appeared to be present in all these samples and to lower the surface tension of these aerosols, allowing them to be turned into cloud droplets. 

“This is really exciting,” says Professor Nozière “because not only this is an indication that there is a direct link between life on earth and cloud formation in the atmosphere, but this also pin points exactly the nature of this link, the organisms and substances responsible for it.” 

“Further study is now required to quantify the contribution of these mechanisms to cloud formation at global scale and to the hydrological cycle .”

With the question of global warming and climate change on many people’s minds, the findings of the Nozière team is likely to spark more debate.

“Cloud cover is the biggest cooling component of our planet,” explains Nozière. “but cloud formation is not well understood. Our finding could be an important step forward in understanding these processes and identify a new link between life on Earth and climate.”

Read an extract from the article in the New Scientist:

www.newscientist.com/article/mg20126903.800-groundbased-bacteria-may-be-making-it-rain.html

Follow the discussion on the web around this article:

Department of Applied Environmental Science (ITM):

www.itm.su.se

Text and interview: Jon Buscall