The challenges posed by climate change have generated a surge of solutions including biofuels. But not everyone is convinced by this 'wonder fuel'.
When Dines Chigabwa surveys the jatropha trees swaying in the fields where she once had cotton and maize, she sees greater prosperity.
"This is a very good crop, because once you plant it you continue reaping; we look forward to more income", says the 54-year-old Chigabwa, who grows the trees together with her husband on most of the four hectares of land they own in central Zambia.
"We see a future in jatropha," Chigabwa says, expressing a sentiment shared by an array of actors who regard the tree as a wonder source for biofuel, the fuel made from plants.
Scientists, oil companies, governments and politicians around the world are promoting biofuel as the energy of the future: a renewable, environment-friendly alternative to crude oil and coal.
In addition to climate change and the urgent need to find a solution, interest in biofuels is fired by high oil prices, political uncertainties in petroleum-producing countries and dire predictions that the world is running out of fossil fuels.
Biofuel was the buzzword at the UN meeting in Nairobi, with industrialised nations showing interest in helping meet international emission reduction targets, and developing countries looking for potential profits from biofuel crops.
"Growing biofuels will be an important part of the development of alternative transport fuels," David Parker, the minister responsible for climate change issues in New Zealand, told the conference.
Countries in Africa, which has the perfect climate for biofuel crops like jatropha, were showing both interest and caution.
"The African continent offers the globe one of the greatest potential options for biofuel production," said Penny Healy, a spokesperson for UK-based D1 Oils, which is running the jatropha project in Zambia.
There alone, the company is looking to expand the 4,000 hectares of jatropha it is growing through independent farmers like Chigabwa by an additional 8,300 hectares before next April.
Zambia has committed 174,000 hectares of land over the next five years to D1 Oils, the company said.
Food or fuel, what choice?
Chigabwa is among 391 small-scale farmers in the Mukonchi region growing jatropha on their own land for D1 Oils.
But at the Nairobi conference, environmentalists and international justice groups warned of the potential dangers of biofuel plantations.
In a statement titled Biofuels: a disaster in the making, a coalition of non-governmental organisations called on conference delegates to separate hype from myth over biofuels.
The coalition points out that the grain required to fill the tank of a single vehicle with biofuel would feed one person for a whole year. But scientists respond that yields will improve with better technology and research.
In 2006, the coalition says, an increase in the use of grain worldwide for conversion to biofuels led to a 60 per cent increase in global grain prices, and attracted speculators to what had previously been a stable market.
"African countries could explore the possibilities of small-scale farming of biofuel crops for households or local energy needs. But the consequences of growing fuel for export to the wealthy developing countries, instead of food for Africans, could be severe," says Teresa Anderson of the Gaia Foundation.
Critics of biofuel also say that the clean air advantages of biofuels are offset by the pollution from fossil fuels that go into growing, processing and transporting biofuels.
Pressure on forests, and indigenous peoples being driven off their native lands to make way for large plantations in developing countries, are other concerns that have been documented in some countries.
"What is being pushed is the economic agenda without looking into the environmental cost [of biofuels]", says Richard Mwendandu, an environmental planner with Kenya's Tana and Athi Rivers Development Authority.
"It is very easy for depressed countries to say we will give you 1,000 hectares for biofuel crop plantations, without taking into account environmental concerns," he says.
Clement Chipokolo, of the Participatory Ecological Land Use Management Association (PELUM), says that biofuel plantations could benefit Zambia's poor, but cautioned about risks.
"The increase in this type of plantation production will certainly affect the already unstable food production in Zambia," where farming and food crises are common, he says.
"Zambia will have to choose between feeding its population… or its ever growing number of cars and industries," Chipokolo says. "The development of biofuels poses risks as well as complex and often expensive trade-offs," he says.
But the farmers of Mukonchi, where Chigabwa is waiting to get rich, say they are still growing food crops like groundnuts and maize alongside their jatropha crops.
"I never saw cotton replace maize, so I think the farmers will continue to grow food alongside their Jatropha crops," says Dr Judith Lungu, dean of the agriculture school at the University of Zambia.
D1 Oils says it is careful to ensure that jatropha does not replace food crops for farmers in Zambia, and it does not plant in nature reserves or protected areas.
Thomson Sinkala, a professor at the University of Zambia's School of Mines, is a proponent of biofuel, and a jatropha farmer himself.
Sinkala says that the biofuels industry does not have to be on a large scale. "Just five per cent of Zambia's non-arable land is enough", he says, noting that jatrophas can thrive on non-arable land unsuited to food crops.
"Villagers will make a lot of money. It is criminal to stop them from improving their lives," Sinkala adds.
Farmers like 58-year-old Dickson Chitundu, who also grows jatropha for D1 Oils in Mukonchi, says one of the problems with the trees is their slow initial growth.
Farmers get the first crop two years after planting, but it isn't until the trees have matured, after about four years, that they yield two crops annually – if weather conditions are good.
Dickson says that farmers are supplementing their income with cotton or food crops as they wait for the first harvest late next year.
Soaring demand fuels interest
Plantations growing jatropha, sugar cane, maize, oil palm and other biofuel crops, have mushroomed in hundreds of projects in developing countries around the world.
Jatropha is popular because it is easy to grow and has multiple local uses: after the oil is squeezed the waste can be used to make fire for cooking, fertilizer, or even animal fodder.
Demand for biofuels is expected to soar as industrialised nations who signed the 1997 Kyoto Protocol look for new ways to reduce carbon emissions to abide by treaty commitments. The European Union says it wants 5.75 per cent of its transport fuel to come from biofuel by 2010.
The United States – which hasn't ratified the Kyoto agreement – is committed to increasing its annual biofuel production from the current 2 billion gallons to 5 billion gallons by 2012.
D1 Oils, which currently runs plantations in South Africa, India, Australia, New Zealand and the Asia Pacific region, is looking to expand operations to China and Central America.
But despite the global frenzy, biofuels proponent Jeff Schafer estimates that if high yield biofuel crops were grown on all the farmlands on earth, they would still only amount to 20 per cent of the world's demand for crude oil.