Sunday, April 26, 2009

Biofuels and Biodiversity

On Thursday I submitted a post on biodiversity and climate change, important ecological trends that compete for the attention of environmentalists. In at least some cases the two topics are linked, either through the potential effects of climate change or various proposed solutions. An example of the latter is biofuel production, which shares many of the ecological problems of industrial agriculture.

A recent paper by Eggers et al. presents a new method of assessing biodiversity impacts resulting from changing land use due to the production of biofuel crops in Europe, distinguishing between arable (first generation) and woody (second-generation) crop types. In particular, Eggers et al. focus on two questions: (1) what might happen if we doubled the current EU biofuel target of 5.75%, and (2) what might happen if we abolished the current biofuel target. While biodiversity as such includes all forms of life, their impact assessment was restricted to a set of 313 species pertaining to four taxonomical groups.

The results indicate that more species might suffer from habitat losses rather than benefit from a doubled biofuel target, while abolishing the biofuel target would mainly have positive effects. However, the possible impacts vary spatially and depend on the choice of biofuel crop, with woody crops being less detrimental than arable crops. The results give an indication for policy and decision makers of what might happen to biodiversity under a changed biofuel policy in the European Union. The presented approach is considered to be innovative as to date no comparable policy impact assessment has been applied to such a large set of key species at the European scale.
Currently biofuel production uses mostly sugar, corn, or other cereals. Multiple studies have shown that biofuel production using these ingredients produces more greenhouse gases per unit of energy than ordinary petroleum, largely because of the high carbon costs of agriculture. Cellulosic ethanol – fuel produced from wood and grass – may be have less lifecycle impact on the climate, and if this study is correct, will destroy less biodiversity as well. The only trouble is that an efficient process for producing these second-generation biofuels awaits invention.

So for now we face an apparent choice between preventing catastrophic climate change and preserving biodiversity. However, given the problems with the current generation of biofuels, this may not be much of a choice at all. It seems to me that both goals warrant slowing the pace of biofuel production until such time as we have a process with less impact on climate and biodiversity.

As an aside, Nate from The Drinking Bird wrote a thoughtful response to the previous article on climate change and biodiversity, particularly the use of palm oil and desert solar arrays.