For Craig Sams, life is sweet. The entrepreneur, who with co-founder Jo Fairley sold the Green & Black’s organic chocolate firm to Cadbury for a reputed £20m, has founded a biochar business, and his firm is about to announce its first deal with the government of the Maldives.

Carbon Gold, Sams’s new company, is to develop biochar projects on three islands in the Maldives, taking waste from agriculture and fishing and turning it into charcoal by roasting it in a low-oxygen atmosphere. The process turns waste into raw carbon, which can then be used to fertilise the soil.

If the trials work out, similar projects could be started on many more of the 200 or so inhabited islands in the archipelago, all part of the Maldives government’s plan to make the islands carbon-neutral by 2020.

A controversial element of the scheme is to use it to generate so-called carbon credits. These are UN-backed certificates that confirm a tonne of carbon dioxide has been prevented from entering the atmosphere, and which can be sold to other countries to offset their emissions. Carbon Gold is working with the Maldives on a plan to sell them to tourists who want to compensate for the carbon dioxide generated by their flights to the holiday destination.

Dan Morrell, who co-founded Carbon Gold with Sams, said the technology had huge promise but needed to be proved in a large-scale trial — and the Maldives deal offered the right opportunity.

“This technology enables us to take invisible carbon dioxide out of the atmosphere, transform it into black lumps of pure carbon and then, by ploughing it into the ground, improve soil fertility,” he said.

Under the scheme, small kilns would be installed in villages across the Maldives, controlled by the villagers, who would use them to dispose of waste and generate energy and fertiliser.

The latter alone could lead to huge savings. The soil in the Maldives is so poor that islanders have to fertilise it with cow dung imported from India at about £60 a tonne.

The Maldives, with a population of 370,000, is already among the nations worst affected by climate change — even though its emissions per person, at two tonnes of carbon dioxide a year, are a fifth of the average Briton’s.

None of the islands lies more than a couple of metres above the ocean and rising sea levels plus associated erosion have already forced the evacuation of two islands. Many more are expected to follow.

If the rise in sea level by 2100 were to reach the one metre or so predicted by scientists, then only two islands would remain inhabitable. One of these is Malé, the capital, which has been protected by a giant wall built by the government of Japan. The other, ironically, is the artificial island of Thilafushi, which has been built entirely of rubbish that was dumped into what was a shallow lagoon and then topped with sand and cement.

Such environmental nightmares are the legacy of Maumoon Abdul Gayoom, who was president of the Maldives for 30 years until he was voted out last November in the country’s first democratic elections for three decades.

Mohamed Nasheed, who replaced him, has announced that the Maldives can no longer consider such approaches. Biochar is one of a raft of technologies he wants to test as a way of disposing of waste and generating energy.

In an interview with The Sunday Times, Nasheed said: “For us climate change is a disaster in the making and we have to set an example if we want the world to change. Biochar could be part of the solution so we want to try it out on three islands.

“Potentially it solves several problems. First, we can use it to get rid of waste from coconut and water-melon plantations. At the moment this is often burnt. We can also use fish waste, which is currently dumped on a reef.

“If it works we can also get heat energy from the process. And then at the end we will have biochar, which can help to improve our soil, which is generally very infertile.”

Biochar is just one of the ideas that Nasheed is backing — he also hopes to end the islands’ dependence on imported diesel for power generation by setting up wind and wave farms.

The news comes amid growing global interest, and controversy, over biochar. At its heart is a process known as pyrolysis in which organic material is roasted in an oxygen-starved environment. This breaks down the complex organic molecules, producing syngas, which can be used as fuel, and leaving behind virtually pure carbon. This can then be ground up and mixed into the soil, where the grains help to retain water and minerals and promote the growth of micro-organisms.

Many environmentalists are suspicious, however, pointing out that the response to climate change so far has been dominated by a search for similar technical solutions — all of which have later turned out to be inadequate.

In the 1990s, for example, the first generation of carbon entrepreneurs promoted the mass planting of trees. The idea withered when people realised the carbon stored in timber would be re-released when the trees died.

More recently, it was biofuels that were hyped — until it became clear that growing and processing them generated more carbon dioxide than using fossil fuels directly. What’s more, the land needed to produce such fuels was taken out of crop production, driving up food prices.

Sams and Morrell stress, however, that they do not see biochar as a global panacea but as just one technology among the many that will be needed.

Sams said: “Biochar can be an important weapon in the battle against climate change and can give mankind much needed time to develop cleaner forms of energy. It cannot be expected to compensate for increasing emission levels so it is vital that everybody plays their part in reducing energy consumption.”

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