Debunking biofuels

Interesting commentary in a letter from Tim Joslin in the most recent edition of the New Scientist (12 Jan).

'You go some way towards debunking the fallacious reasoning used to justify
biofuels as a way of reducing greenhouse gas emissions (15 December 2007, p 6 and p 3) - but there is more. The net greenhouse gas saving for current biofuel
crops in temperate regions is not more than a tonne of carbon per hectare per
year - and is sometimes negative. But we need to take account of the opportunity
cost of the land on which biofuel crops are grown. Reforestation, for example,
could remove at least tens of tonnes of carbon per hectare from the atmosphere:
so the payback period is decades at best. Even in the tropics, annual greenhouse
gas savings are a few tonnes per hectare, at most. Growing biofuels may
require land to be cleared, perhaps indirectly: for example, because food
production has been displaced by the biofuel crop. Land clearance results in
immediate greenhouse gas emissions, whereas the biofuel savings occur over
time. Then there are the issues of displacement pointed out in the letter
from Elliott Spiker (15 December 2007, p 18). Using biofuels may merely free up fossil fuels for someone else to use, perhaps in another country. National governments and the European Union should abandon all subsidies and quotas for biofuels forthwith.'