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New study distils the eco footprint of biofuels


September 30, 2012

A new study by Swiss research group Empa found that some biofuels, especially the ones made from crops cultivated on deforested land, produce more GHG emissions than petrol (Photo: Shutterstock)

A new study by Swiss research group Empa found that some biofuels, especially the ones made from crops cultivated on deforested land, produce more GHG emissions than petrol (Photo: Shutterstock)

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The controversial debate over the sustainability of biofuels has been reignited by new research from Swiss-based research institute Empa. While the study maintains that biofuels can be sustainable depending on certain conditions and the technology involved, the findings suggest that only a few are more environmentally friendly than gasoline.

The study entitled Harmonisation and extension of the bioenergy inventories and assessment was carried out by the Swiss Federal Laboratories for Materials Science and Technology (Empa) in conjunction with the Institute Agroscope Reckenholz-Tänikon (ART), and the Paul Scherrer Institute (PSI). It is an update on a first of its kind report compiled in 2007, made more relevant for the present with new energy plants, manufacturing processes and updated assessment methods. Yet, the researchers arrived at a similar conclusion.

Although biofuels can have a smaller carbon footprint compared with fossil fuels, they produce other types of environmental pollution, including soil acidity and excessive levels of fertilizers finding their way into lakes and rivers.

More alarmingly, biofuels from deforested areas have a bigger greenhouse gas (GHG) footprint than fossil fuels. This is also true of indirect land usage – if existing agricultural land is used for the first time for a biofuel crop, new areas will have to be cleared to make up for displaced food and animal feed crops.

Empa overview of the environmental impacts of various biofuels relative to petrol

“Most biofuels therefore just deflect the environmental impact: fewer greenhouse gases, thus more growth-related pollution for land used for agriculture,” says Empa researcher Rainer Zah.

Biogas made from residues and waste materials performs particularly well in terms of reducing emissions, having up to half the environmental impact of gasoline. Meanwhile, ethanol-based fuels tend to be greener than those biofuels with an oil base. Nevertheless, any environmental advantage or disadvantage is dependent on how the fuel is manufactured and the technology involved.

Besides the methodological updates, the new report also fixed some "weaknesses" of the previous report, where the researchers underestimated how much changes to natural areas, such as the deforestation of the rainforest, impacted on GHG balance.

On a positive note, biofuel crops can increase the carbon content of the soil. As examples, the report cites the cultivation of oil palms on unused grazing land in Colombia or jathopha plantations in India and eastern Africa, where deserted land has been transformed into arable areas. However, the report's authors warn that all these benefits depend on the type of agriculture being practiced and the land’s previous use, with each biofuel type needing to be analyzed individually.

The report also includes some general advice on what to do to avoid the most adverse ecological results from biofuel production. Clearing forests and bush areas is an obvious no-no. In the case of agricultural land, indirect change of land is also bad practice. Finally, second generation biofuels, based on residues such as straw, garden and timber waste can be environmentally sound if they are not being diverted from other uses and if their extraction does not compromise soil fertility and biodiversity.

The report can be downloaded via the link below.

Source: EMPA

About the Author
Antonio Pasolini Brazilian-Italian Antonio Pasolini graduated in journalism in Brazil before heading out to London for an MA in film and television studies. He fell in love with the city and spent 13 years there as a film reviewer before settling back in Brazil. Antonio's passion for green issues - and the outdoors - eventually got the best of him and since 2007 he's been writing about alternative energy, sustainability and new technology. All articles by Antonio Pasolini

Would be interested in how the comparison to oil was made, for example water ecotoxicity, since haveing >167% the impact of Deepwater Horizons spill in the gulf or the toxification of the Athabasca River due to tar sands is difficult to imagine.

Max Kennedy

The "Study" does not bring in Hemp When you extract oil from hemp seeds you also get flour so there is no fuel vs food conflict. Hemp does not need fertilization of the soil to grow a good crop in fact it grows just fine in substandard soils with little water and no fertilizer this means you can develope land that was unavailable for food or fuel. In raising hemp you get the benefit of it's stalk that produces cloth quality fiber that could take the place of cotton a fuel fertilizer pesticed intense operation to grow. For those who don't know Hemp is not Marajuana you can not get high from hemp and Marajuana is a short scrubby bush type plant and hemp is a tall skinny type plant and are simple to tell apart.

Joseph Mertens

I don't think anyone ever suggested that bio-fuels were any cleaner. Just that they are renewable.


Effective chart. I have had my doubts about biofuels being sourced as a primary function of the agriculture. It's benefit comes from using otherwise waste material, such as sewage or vegetable waste from cropping as rightly highlighted by Antonio Missing is the use of algae, and in particular the broad acreage proposals as is being researched by Aurora Algae in Karratha. This uses salt water ponds to grow algae to be used for oil generation. Certainly, the biofuel argument is more from it's renewability aspect. The problem of eager hope is misplaced expectations. This is an important study, and one worth the global community to invest in other parallel studies to compare results.


This report appears to objectify what is essentially subjective, and relies on some rather tenuous dependencies. I don't really think people should get paid for this type of "research".


It really highlights that you're best off increasing efficiency by making use of what otherwise would be waste product. eg: sewage sludge and wood chips. Using wheat, corn or sorghum is obviously ineffective because you should use that as food. People turn food into energy much more efficiently when you take into account we need it to live anyway.


I never thought it was a good idea to deforest jungle to grow alternative fuels, this only supports that. Let's hope that biofuels generated this way are only transitional until we can get algae production to commercial levels. Most biofuels are very inefficient anyways providing at most a couple hundred gallons per year per acre. Algae should be at least 10 times that, with considerably lower cost and really no need for pesticides or any of the other environmentally damaging practices. It's just that no one has yet to really succeed at it.


nutcase, isn't your statement essentially subjective.


Yes katgod the second statement is purely subjective, but read the article where it says things like "if existing agricultural land is used for the first time for a biofuel crop, new areas will have to be cleared to make up for displaced food and animal feed crops". This is rubbish. In my experience (I live in an agricultural region) farmers are more likely to plant biofuel canola rather than wheat when the market is favorable. If market forces were purely objective rather than highly subjective then primary industry would be easy, with only the weather to contend with.


This study does not seem to include any bamboo. A shame.

Jim Hinds
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