This is a fascinating report that just published in the reputed journal Science. I read this at the Green Car Congress. I am, frankly, quite surprised by this very high value to total lifetime CO2 burden from biofuels. I am aware of studies arguing that the direct production of ethanol from crops such as corn has a potentially net negative energy balance, but this large negative impact of global biofuels production is really a big worry. I look forward to follow up studies.
Researchers at the University of Leeds (UK) and the World Land Trust have concluded that up to nine times as much carbon dioxide could be emitted using biofuels compared to conventional gasoline and diesel because biofuel crops are typically grown on land which is burnt and reclaimed from tropical forests.
In a report in the journal Science, the authors conclude that protecting and restoring natural forests and grasslands is a much better way to reduce carbon dioxide emissions.
This study shows that if your primary concern is reducing carbon dioxide emissions, growing biofuels is not the best way to do it. In fact it can have a perverse impact elsewhere in the world. The amount of carbon that is released when you clear forests to make way for the biofuel crop is much more than the amount you get back from growing biofuels over a 30-year period. You can’t convert your car to run on biofuel and keep on driving and think that everything will be OK. You are turning a blind eye to what’s happening around the world and that in fact, you could be making things much worse.
—co-author Dominick Spracklen of the School of Earth and the Environment at the University of Leeds
The study compared the amount of carbon dioxide emissions that would be saved from entering the atmosphere by growing biofuels with the amount saved from slowing deforestation and restoring forests over a 30-year period.
The study also found that converting large areas of land back to forest provides other environmental benefits such as preventing desertification and regional climate regulation. The conversion of large areas of land to make biofuels will place further strains on the environment, the study concluded.
European Union member states have pledged to replace 10% of transport fuel with biofuel from crops by 2020 in an effort to reduce reliance on imported oil and reduce carbon dioxide emissions. Meeting the EU target would require an area larger than one third of all the agricultural land in Europe to be used for growing biofuel crops, assuming no imports.
Over a quarter of CO2 production globally comes from transport and moving to carbon-free transport fuels presents some of the most difficult technical problems. While there are solutions like hydrogen in the offing, it will probably be 30 years or more, before the bulk of transport fuel could be replaced. Liquid biofuels offer a superficially attractive option because they can be used by existing cars and lorries and use the existing fuel distribution system. Powerful agricultural lobbies have seized on this as a substantial growth opportunity and governments see it as way of reducing dependence on oil imports or as a large export opportunity. In Europe, biofuels are seen as a way of meeting the EU “renewables” obligation. We believe that the current rush into biofuel production is misguided—it is a risky and ineffective strategy for reducing CO2 levels and it is destroying natural habitats rich in biodiversity.
—co-author Renton Righelato, on World Land Trust’s biofuels policy
- Renton Righelato and Dominick V. Spracklen; “Carbon Mitigation by Biofuels or by Saving and Restoring Forests?”; Science 17 August 2007: Vol. 317. no. 5840, p. 902 DOI: 10.1126/science.1141361