The Helix, Australia's premier science education magazine since 1986.
UK Biofuel Debate:
The UK has embarked on an audacious new scheme to lessen the country’s fossil-fuel dependency and to minimise climate change. But not everyone is in favour.
From April 15, all petrol and diesel sold in UK pumps must contain at least 2.5% biofuel. The target is set to rise to 5% by 2010, with the motive to make Britain's 33 million vehicles greener. But critics argue that the benefits from the scheme may be outweighed by the negative effects of biofuel production, which results in forest clearing, the loss of habitat, and may indeed speed up climate change.
Biofuels are made from renewable biological sources such as sugar cane or maize, and can have advantages over traditional fossil fuel sources as, when they are burnt, they only release the carbon dioxide they absorbed from the atmosphere during their lifetime. In contrast, fossil fuels release massive quantities of carbon locked out of the Earth’s carbon cycle for millions of years.
Whilst burning biofuels adds less carbon to the atmosphere than burning fossil fuels, biofuels require extensive land clearing. This could involve cutting down established forests that absorb much more carbon dioxide than the newly planted biofuel crops. Additional carbon dioxide may escape from the soil or peat, where it was trapped by the roots of trees.
Researchers at the University of Minnesota published a study in February arguing that converting Brazilian, Southeast Asian and US rainforests, peatlands, savannas, and grasslands to produce biofuels will release 17 to 420 times more carbon dioxide than the fossil fuels they replace.
Apart from the climate change implications, there may be catastrophic conservation consequences for not only virgin forests, but also animal species. In South America, sugar cane production for biofuels has wiped out the habitat of the large Alagoas curassow, making it extinct.
The other major problem with the move towards biofuels is food security. Poorer countries are now switching land previously used to grow food crops to more profitable biofuel crops. The UK, which sources much of its produce from overseas, has already seen food prices rise.