In our most recent podcast Professor Jason Hill spoke about the role that biofuels can play in the future of sustainable development. He is rightly concerned about the impacts that biofuel development may have on deforestation rates and land-use change around the world. As he mentions, a full accounting of the life-cycle costs of biofuels, especially corn ethanol, suggests that they may not represent as significant a reduction in carbon emissions as previously thought. Depending on whose model is used, biofuels may, in fact, not result in any reduction in carbon emissions over traditional fossil fuels. This is due, he says, in large part to the increased deforestation that may be caused when food production is displaced by biofuels production.
While significant, the increased carbon emissions that result from this increased deforestation are not the only, or even most important, reason to be concerned about biofuels production displacing food production. Increasing rates of deforestation and habitat change, driven by the need for more biofuels, pose an existential threat to biodiversity. This is especially true when these land use changes take place in biodiversity hotspots like the Amazon basin, the Gran Chaco & Pantanal, – a wetland ten times the size of the Everglades – or the rainforests of Indonesia. And as one recent study on the biodiversity impacts of biofuels points out, the extinction of species in these unique habitats caused by the expansion of farming cannot be offset by action elsewhere.
Dr. Hill briefly touches on the dangers that biofuel production poses to biodiversity at the close of the interview, but he does not provide specifics or fully detail the scope of the threat. This is in part because the full scope of the threat is not known. The same challenges that exist when modeling the full carbon impact of biofuels also exist in attempts to measure the biodiversity impacts. As Dr. Hill explains, it is difficult to attribute the lost of this acre of rainforest to the use of that acre of corn as biofuel instead of food. However, a recent estimate suggests that the biofuel goals of the EU alone threaten 85% of biodiversity across 17,000 sq km.
As greater accuracy in modeling the land use impacts of biofeuls is reached, it is likely that their measured impacts on biodiversity will continue to grow. As a result, the negative impacts that some biofuels – namely those which are produced from food stocks – may spell their demise. These fuels are most useful as a bridge fuel; by offering marginal carbon improvements over fossil fuels that reduce carbon emissions, they allow the economy to transition to a carbon free source of energy. Because of their high carbon content foodstock, biofuels were never meant to be a permanent replacement for fossil fuels. Unfortunately, if their use as a bridge fuel incurs permanent losses of biodiversity in the form of extinctions, their usefulness even as a bridge fuel is compromised.
Despite the threats that some biofuels pose to biodiversity, they should not be written off entirely. Dr. Hill mentions the potential for using native grasses with deep, carbon fixing roots, as a source of biofuel in the future. In addition to the carbon benefits that this type of plant offers, a resurgence of native grasslands in the U.S. Midwest would be a boon for biodiversity and aid one of the most degraded habitats in the world – the American prairie, 99% of which has been destroyed.
The momentum pushing the development of corn, soy, and other foodstock biofuels may slow due to the frictions pointed out by Dr. Hill: ambiguous, and perhaps non-existent carbon benefits and threats to food security. It seems that outside the American Midwest this may already be happening. In addition to these serious challenges, the threat that foodstock biofuels pose to global biodiversity must ultimately stop their development. Instead, we should focus on biofuels that promote native species, do not crowd-out food production, and are net carbon negative; doing so might finally yield an energy source that does not threaten the planet.