Standards Deficient for Current Biofuels

Biofuels offer a unique opportunity for the developing world. Almost 80 percent of the remaining land that has cultivation potential resides in South America and Africa, according to research supported by the United Nations.

However, without a standard method for determining the impact of biofuels on the environment, international bodies like the U.N. will tread carefully when discussing the role of bioenergy in mitigating the effects of climate change, despite the potential economic benefits for the developing world.

The future of bioenergy from algae and bioengineered feedstocks is an exciting and promising opportunity for life science to take a larger role in sustaining our energy needs.

In the meantime, much of the focus remains on first and second generation biofuels made from corn, sugarcane and cellulosic feedstocks. These are a controversial renewable energy source due to the various estimates regarding the impacts of indirect land-use change on the environment.

In 2008, Searchinger et al. caused a stir in the debate over corn ethanol by publishing a study that indicated the feedstock doubled CO₂ emissions over a 30-year period when compared to fossil fuels.

In the same issue of the journal Science, Fargione et al. defined the carbon debt for a number of feedstocks, where carbon debt is the amount of time the feedstock takes to produce less CO₂ than the fossil fuels they are replacing. In the study, corn ethanol had a carbon debt of a staggering 93 years. Combined, these stories pushed the issue of indirect land-use change to the forefront of the debate on biofuels and climate change.

Earlier this year, Liska & Perin debunked the Searchinger study by highlighting the sensitivity of its conclusions along with omitted benefits including emission reductions due to estimated livestock reduction, which would offset half of the additional emissions from corn ethanol.

In August of this year, Sandia Laboratories released a paper showing that the United States could produce 90 billion gallons of ethanol per year by 2030, or 50 percent more than the current target. Corn ethanol was not the bulk of the supply but did account for more than 15 percent of the total.

Meanwhile, contributors to the Gigaton Throwdown (an initiative to scale up clean energy) chose not to consider corn ethanol as a biofuel feedstock precisely because of the indirect land-use change controversy.

As some reputable researchers want to include corn ethanol in the biofuel mix, others are avoiding the topic until a body defines clear standards related to indirect land-use change. Last week, the Council on Sustainable Biomass Production (CSBP) released a draft standard for bioenergy, which includes indirect land-use change.

Until an agreed upon standard for indirect land-use change exists, such as the one proposed by the CSBP, the effects of biofuels on climate change will remain controversial. Proponents of first generation biofuels will continue to understate the indirect land-use change problem by highlighting the economic benefit to developing nations, the exclusive use of land that is non-forest and marginal, and the potential increase in energy security by diversifying transportation fuel away from oil.

[chart credit: Nick Nigro]