T wo scientists from Oxford University have a hunch that something called biochar — which some say is simply a fancy name for charcoal — could solve the problem of how to feed the world’s burgeoning population and cut back on carbon emissions at the same time.

And they are so convinced of the efficacy of the product they have set up a company to sell it. Founders of Oxford Biochar, Dr Cécile Girardin, of Oxford University’s Environmental Change Institute (ECI), and Dr Russell Layberry, also an ECI scientist, have made the substance available online through their website and selected outlets — including the Burford Garden Centre They are also acting as consultants to farmers with a view to seeing it used on a wider scale in agriculture. And as well as selling it they are carrying out a nationwide survey to test whether it really might be an answer to global climate change and agricultural problems — as some reputable scientists claim.

Dr Girardin, who made a study of carbon tracking in south American rainforest soils for her PhD, said: “We are scientists and so we are never convinced — which is why we are carrying out this survey. But at the moment we have 200 people testing biochar, all of whom have received free samples.”

She added: “It is certainly true that native Amazon peoples were using biochar long before Columbus discovered America.

“There are traces of it in the rainforest, known as terra preta (black soil). And we think it may be valuable in the future.”

Biochar is produced by a process called pyrolisis, basically burning wood without oxygen.

Oxford environmentalist Chris Goodall explained exactly why he reckons that putting it into soils could be a carbon-negative activity and therefore potentially hugely beneficial to the planet.

He said: “Imagine a tree, say, growing in Wytham Woods. As it grows it takes carbon from the atmosphere. In time it dies and rots away.The process of rotting is oxidisation, and that process puts carbon dioxide back into the atmosphere.

“By cooking the wood without oxygen, however, it is reduced to inert carbon — and such gases as hydrogen that are given off can be used to power the heat.

“If you then bury the resulting biochar in the soil you have then trapped the carbon and I believe in some soils it can very significantly help the development of roots in some crops.”

He added that Cécile Girardin is a world expert on soils and carbon and that he fully supports her efforts to show how and why and when biochar could be useful.

Hype around the product has recently divided scientists but green guru and chemist Prof James Lovelock — author of the Gaia theory, which maintains that all things on earth are part of a single self-regulating whole — gave the pro group a fillip recently.

He said: “There is one way we could save ourselves and that is through the massive burial of charcoal. It would mean farmers turning all their agricultural waste — which contains carbon that the plants have spent the summer sequestering — into non-biodegradable charcoal and burying it in the soil. Then you can start shifting really hefty quantities of carbon out of the system and pull the CO2 down quite fast.”

But in the anti-biochar camp, opponents say that exploiting it could lead to further destruction of forests as people take wood to make it.

In other words, the old adage if something seems too good to be true, it probably is too good to be true, applies to this seemingly miraculous answer to the world’s greatest environmental problem.

But all agree that there is no harm in investigating the idea further.

Apart from founding Oxford Biochar Ms Girardin and Mr Russell have obtained more than £3,000 for their research from the website Peoplefund.it.com, founded by television cook Hugh Fearnley-Whittingstall.

Peoplefund.it is a new crowd-sourcing website from the makers of the TV series River Cottage which brings together individuals with fresh ideas with concerned members of the public willing to back them — sometimes with as little as £1.

It works in partnership with Forum for the Future, the organisation set up by Jonathon Porritt, former chairman of the UK Sustainable Development Commission and Friends of the Earth, to work globally with business and government to create a sustainable future.

Commenting on Oxford Biochar, Rob Love, managing director of River Cottage, said: "Hugh and the team are delighted at Oxford Biochar's success. It is an innovative product and we intend to use some at River Cottage headquarters at Park Farm in Axminster.”