We might think we control the climate but unless we harness the powers of our microbial co-habitants on this planet we might be fighting a losing battle.

Humans mostly affect the atmosphere indirectly by our activities. Most human-induced methane comes from livestock, rice fields and landfill but in all of those places, microbes are actually responsible for producing the methane, 150 million tons per year. Microbes in wetlands produce an additional 100 million tons and those that live inside termites release 20 million tons of methane annually.

90 billion tons of carbon per year is absorbed from the atmosphere by the oceans, and almost as much is released; microbes play a key role in both. On land, a combination of primary production, respiration and microbial decomposition leads to the uptake of 120 billion tons of carbon every year and the release of 119 billion tons.

“The impact of these microbially-controlled cycles on future climate warming is potentially huge,” says Dr. Dave Reay from the University of Edinburgh.

By better understanding these processes we could take more carbon out of the atmosphere using microbes on land and in the sea. Methane-eating bacteria can be used to catch methane that is released from landfill, Cyanobacteria could provide hydrogen fuel, and plankton have already become a feedstock for some biofuels.

“Microbes will continue as climate engineers long after humans have burned that final barrel of oil. Whether they help us to avoid dangerous climate change in the 21st century or push us even faster towards it depends on just how well we understand them.”

Article in the February 2008 issue of Microbiology Today