How's this for a quote:
"While on a small scale biofuels may be beneficial
by supplementing fuel supply, promoting
their use to unsustainable levels under current
technology is problematic, and long-term prospects
for biofuels depend heavily on how quickly
and efficiently second-generation substitutes
(such as plant waste) can be adopted. Many
energy market analysts also question the rationality
of large subsidies that benefit farmers more
than the environment. While new technology is
being developed, a more efficient solution from
a global perspective would be to reduce tariffs on
imports from developing countries (for example,
Brazil) where biofuels production is cheaper and
more energy efficient."
That's found on page 45 of the World Economic Outlook, Ch. 1 (appendix)
