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Biofuel: silver bullet or fool's gold?

Can biofuels meet the energy needs of the poor?
Can biofuels meet the energy needs of the poor?

With rising oil prices and global insecurity, the growing of biofuels has been hailed as a means to reduce dependence on fossil fuels whilst revitalising rural economies and tackling climate change. However, widespread cultivation of fuel crops remains controversial, with critics fearful of the impact on ecosystems and biodiversity, and disputing their potential to raise incomes among the poor.

Taking more than they give?

In analysing the environmental credentials for biofuels, deciding which crop to grow - and how - are key. Maize, the leading biofuel crop in North America, is produced using large-scale fossil fuel based production systems. The energy yield for maize is also relatively low: each unit of energy used to produce maize-based ethanol yields only 1.5 units of energy in fuel. Compared with Brazilian sugarcane, which produces eight units of energy for each one invested, maize-based ethanol looks like a questionable alternative - although one that is currently supported by North American maize subsidies. Oilseed rape and soybean are slightly better, offering 2.5 to 3 units of energy per each unit invested. Biodiesel derived from palm oil is even more efficient, although production of soybean and palm oil crops are both highly criticised for their impact on the environment.

Grown with little or no chemical inputs Jatropha and sweet sorghum are attracting interest in India. Switchgrass, a wild prairie grass, could offer North America an attractive alternative to maize or soybean. As a perennial crop there is reduced need for energy-costly ploughing, and production of ethanol from its cellulose (rather than plant sugars), offers a high net energy yield. Once cellulose conversion technology has matured - which analysts believe could take 10-15 years - production of liquid fuels from a wide variety of agricultural biomass, including wood chips, grasses, crop residues and seaweed should be possible.

Losing natural habitats and biodiversity

However, without tight restrictions on land use, Lester Brown of the Worldwatch Institute has warned that high oil prices could become the leading threat to biodiversity. Yet fuel crops can be used to benefit rather than destroy the environment. With cellulose conversion technologies, grass and tree crops grown for liquid fuel could be used to restore degraded land. Algae farms are another biofuel option that need relatively small amounts of land, and much less water than a field crop. Located close to power stations, exhaust gases from the station are passed through water tanks where algae absorb the CO2 to produce an oil for use as fuel. Once the oil is extracted, the remaining biomass becomes a feedstock for ethanol production. The technology is particularly appropriate for desert areas, such as in south western US and parts of China, two countries where reducing CO2 emissions is critical.

Poverty reduction

Strong government support will be essential if biofuels are to become a viable industry, and to minimise competition with food crops. Significant investment will be needed in cultivation, fuel production and distribution, and vehicle modification. In 2006 the International Bioenergy Platform (IBEP) was established to advise governments and private industry on how to ensure that poorer farmers benefit from biofuels. Without such efforts, large-scale farms and agribusiness will inevitably monopolise biofuel production subsidies, with smallscale farmers gaining little.

Plant breeding programme for Jatropha (DI Oils)
Plant breeding programme for Jatropha
DI Oils

Promoting crops that grow on marginal lands is one way governments can involve the poor. This would also reduce the impact of biofuels on food production. However, without land use restrictions, prime agricultural land may be turned over to fuel crops, reducing food availability and potentially pitting the interests of the world's transport industry against the food needs of the poor. Global prices of palm oil and sugar have already increased due to their increasing use in fuel. Whilst good news for some growers, this increases the burden of the poor, who spend more on food than energy compared with the wealthy, and who are therefore more disadvantaged by high food prices, even if energy prices fall. Choosing crops like sweet sorghum and coconut, which offer an energy yield and a food or feed crop, reduces the impact on food production. In China, biogas is used to heat greenhouses, thereby increasing vegetable production and food availability.

Despite recent directives to increase biofuel production, certain regions may simply not be appropriate for large-scale biofuel production. Figures from the OECD suggest that European countries would need to convert 70 per cent of their arable land to biofuel to provide 10 per cent of their fuel requirement. For temperate climates, a more logical option may be to continue using some fossil fuels, pay carbon offsets, and import biofuel from overseas. Tropical and subtropical countries, capable of year-round production of crops such as sugarcane, have a key advantage which could make them the big fuel providers of the future. However, tight control at national and international level will be needed if the poor and the environment are not to be sacrificed in the race to fuel the future.

Date published: November 2006

 

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The New Agriculturist is a WRENmedia production.

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