Do bugs in clouds control the weather? `Grey skies` research project launched to explore aerial ecosystems

Researchers from the University of East London (UEL) have embarked on a project to investigate the ecology of the atmosphere, one of the last great frontiers of biological exploration on Earth. In an eighteen-month pilot project launched today, a team of microbiologists led by Dr Bruce Moffett aims to discover whether airborne microbes play an active role in forming clouds and causing rain to fall.

The researchers are using a revolutionary `cyclonic cloud catcher`, based on vacuum cleaner technology, to sample cloud water from aircraft and on uplands across the British Isles. The samples are then analysed using a technique developed in medical research known as real-time PCR (polymerase chain reaction) to discover the composition and activity of the microbial communities present.

The research is funded by a £130,000 grant from the Natural Environment Research Council (NERC). On Weds 22nd May, the team used a prototype cloud catcher mounted on a NERC research plane to collect a number of samples from low-lying cumulus cloud near Oxford, and preliminary analysis has indicated the presence of micro-organisms including ammonia-oxidising bacteria.

It is known that bacteria, fungal spores, algae and other micro-organisms survive and possibly reproduce in the harsh conditions of the atmosphere, but scientists have until now been unable accurately to detect, identify and analyse these microbial communities. The UEL team aims to test the theory that an active, self-sustaining ecosystem exists in the clouds, and that bacteria and algae play a key role in the processes that create clouds and trigger rainfall.

Bruce Moffett said: “we know that the balance of gases in earth`s atmosphere has been generated and sustained by microbial activity during the 3.5 billion years since life evolved. We are looking for evidence that microbial metabolism could have a major influence on patterns of climate and weather today. A really exciting possibility is that microbes have evolved ways of triggering cloud formation and rainfall to facilitate their own dispersal and reproduction, in other words, they could be controlling the weather.”

Dr John Baker, Deputy Director of Science Programmes at NERC, said: “We are very pleased to be able to fund this innovative project, which will provide answers to long-standing questions in meteorology”.

Investigating this vast unexplored realm of the biosphere has huge potential practical benefits. New species discovered in these extreme conditions could prove to be a significant resource for biotechnology and medical research. Some of the microbes may have natural screening against UV rays or processes to neutralise greenhouse gases. The research will also help scientists understand the movement of airborne pathogens such as the foot and mouth virus, and phenomena such as `red tide` toxic algal blooms. Other possible applications include `organic` microbial cloud seeding in arid regions.

Dr Tim Lenton of the Centre for Ecology and Hydrology in Edinburgh, who worked with the late Professor Bill Hamilton on `Spora and Gaia`, an influential paper that focused attention on this topic, is also helping develop the new project. He said: “We are aiming to discover whether microbes that trigger condensation and freezing are active in clouds and thus influencing the weather. The potential implications are profound, and could provide more evidence for the `Gaia hypothesis` that the Earth`s climate and atmospheric composition are regulated by biological processes”.