The news that the UK is to slow the adoption of biofuels, and that the European Parliament has called for a reduction in the EU’s targets for biofuel adoption, is a good point to mark one of the most rapid turnarounds we’ve seen in science policy. Only two years ago, biofuels were seen by many as a benign way for developed countries to increase their energy security and reduce their greenhouse gas emissions without threatening their citizens’ driving habits. Now, we’re seeing the biofuel boom being blamed for soaring food prices, and the environmental benefits are increasingly in doubt. It’s rare to see the rationale for a proposed technological fix for a major societal problem fall apart quite so quickly, and there must surely be some lessons here for other areas of science and policy.
The UK’s volte-face was prompted by a government commissioned report led by the environmental scientist Ed Gallagher. The Gallagher Review is quite an impressive document, given the rapidity with which it has been put together. This issue is in many ways typical of the problem we’re increasingly seeing arising, in which difficult and uncertain science comes together with equally uncertain economics through the unpredictability of human and institutional responses in a rapidly changing environment.
The first issue is whether, looking at the whole process of growing crops for biofuels, including the energy inputs for agriculture and for the conversion process, one actually ends up with a lower output of greenhouse gases than one would using petrol or diesel. Even this most basic question is more difficult than it might seem, as illustrated by the way the report firmly but politely disagrees with a Nobel Laureate in atmospheric chemistry, Paul Crutzen, who last year argued that, if emissions of nitrogen oxides during agriculture were properly accounted for, biofuels actually produce more greenhouse gases than the fossil fuels they replace. Nonetheless, the report finds a wide range of achievable greenhouse gas savings; corn bioethanol, for example, at its best produces a saving of about 35%, but at its worst it actually produces a net increase in greenhouse gases of nearly 30%. Other types of biofuel are better; both Brazilian ethanol from sugar cane and biodiesel from palm oil can achieve savings of between 60% and 70%. But, and this is a big but, these figures assume these crops are grown on existing agricultural land. If new land needs to be taken into cultivation, there’s typically a large release of carbon. Taking into account the carbon cost of changing land use means that there’s a considerable pay-back time before any greenhouse gas savings arise at all. In the worst cases, this can amount to hundreds of years.
This raises the linked questions – how much land is available for growing biofuels, and how much can we expect that the competition from biofuel uses of food crops will lead to further increases in food prices? There seems to be a huge amount of uncertainty surrounding these issues. Certainly the situation will be eased if new technologies arise for the production of cellulosic ethanol, but these aren’t necessarily a panacea, particularly if they involve changes in land-use. The degree to which recent food price increases can be directly attributed to the growth in biofuels is controversial, but no-one can doubt that, in a world with historically low stocks of staple foodstuffs, any increase in demand will result in higher prices than would otherwise have occurred. The price of food is already indirectly coupled to the price of oil because modern intensive agriculture demands high energy inputs, but the extensive use of biofuels makes that coupling direct.
It’s easy to be wise in hindsight, but one might wonder how much of this could have been predicted. I wrote about biofuels here two years ago, and re-reading that entry – Driving on sunshine – it seems that some of the drawbacks were more easy to anticipate than others. What’s sobering about the whole episode, though, is that it does show how complicated things can get when science, politics and economics get closely coupled in situations needing urgent action in the face of major uncertainties.