Earth's microbial lungs may be encouraged to take deeper breaths to rid the atmosphere of pollution, writes Roger Highfield from London.
The Earth's atmosphere is so polluted that the planet is dying. But scientists around the world have a plan; they want to enlist some of the smallest creatures to renew the atmosphere and save all of humanity.
The US has already spent about $US100 million dollars to curb climate change by giving the Earth a new set of "lungs".
The lungs would consist of vast colonies of bacteria and other microbes that are able to scrub the atmosphere of greenhouse gases such as carbon dioxide and methane. As a bonus, they may even convert the pollutants to ethanol, which can be used as a fuel.
Last year, Spencer Abraham, the US Secretary of Energy, said he envisaged "a colony of specially designed microbes living within the emission-control system of a coal-fired plant, consuming its pollution and its carbon dioxide".
Dr Ari Patrinos, director of the US Department of Energy's biological and environmental research program, is confident that microbes - and their extraordinary biochemistry are up to the job of altering the atmosphere of the planet.
After four billion years of evolution, microbes now make up 60 per cent of the mass of living material on the planet. Each of us relies on several kilograms - consisting of many thousands of species - in our gut to digest food. Trees breathe in carbon dioxide thanks to microbial colonies. The same goes for the oceans, said Dr Patrinos.
He concedes that the idea of persuading the planet's microbial lungs to take deeper breaths sounds "too science-fiction and far-fetched". The goal of the "Genomes to Life" project is to understand how living things manage their astonishing metabolic feats.
Earlier this year, the US DoE brought together 80 scientists to discuss the plan, the outline of which is straightforward. Read the entire genetic codes - genomes - of microbes, trees and thousands of other creatures that deal with pollution and then see if there is a way to harness them or their clever chemistry in clean-ups or even design one from scratch.
One of those present at the Washington meeting was Professor Jeremy Nicholson of Imperial College London, who said he felt as if he was "part of a science-fiction movie".
"US scientists have probably hit on an idea that may just be practical," he said. A study of one microbe by Professor Jim Barber at Imperial College London is helping to show how it influences carbon dioxide levels. "What factors influence this bacterium's ability to regulate carbon dioxide is crucial for humans' continued survival," he said.
At the Institute for Biological Energy Alternatives, in Rockville, Maryland, Dr Craig Venter has been working on the creation of a microbe with the minimum number of genes to survive, which could lead to the creation of artificial organisms to turn carbon dioxide to ethanol or make hydrogen fuel.
An effort to re-engineer the way that the Earth cycles greenhouse gases "could be the world's most ambitious and scary science project - literally to re-terraform our planet's atmosphere, using a giant microbial supercolony", Professor Nicholson said. The ultimate projected cost could be 100 times greater than that involved in putting man on the moon.
The lungs might have to be capable of capturing from the atmosphere 300 million tonnes of carbon dioxide a year.
"You might need billions of tons of bugs to do this," he said.