ZURICH, SWITZERLAND – The first worldwide ecobalance study of biofuels was carried out in 2007 by the Swiss federal research group Empa, which this week released results of a second study. The news shows just how far we have to go before finding green alternatives to petrol, says the Zurich group.
Empa is part of the ETH Domain, which includes EPFL in Lausanne, ETH in Zurich, four research centres (PSI, WSL, Empa and Eawag), a board and an independent appeals body.
“Empa comes to the same conclusion as the study in 2007: many biofuels based on agricultural products indeed do help to reduce the emission of greenhouse gases, but lead to other environmental pollution, such as too much acid in the soil and polluted (over-fertilised) lakes and rivers.
“‘Most biofuels therefore just deflect the environmental impact: fewer greenhouse gases, thus more growth-related pollution for land used for agriculture’”, says researcher Rainer Zah, who also led the first study.
The 2012 study included both innovative energy plants and manufacturing processes and also updated assessment methods.
Switzerland’s federal Energy Office defines biofuels as:
“motor fuels in liquid or gas form that are obtained from biomass. Other terms used for biofuels include agrofuels, alternative fuels, ecofuels. The following fuels can be obtained from biomass: biogas, vegetable oil, biodiesel/rapeseed methyl ester (or RME), bio-ethanol, bio-methanol, and ‘sun fuels’ (biomass-to-liquid, or BTL fuels).”
A new look at the effect of changes to natural areas on greenhouse gas balance
A key point made by the study is that to realistically assess a biofuel’s impact they must each be studied individually because site use varies so much from one place to the next.
“The researchers in 2007 underestimated the effects of changes to natural areas on the greenhouse gas balance, for example the deforestation of the rain forest. The current study now shows that biofuels from deforested areas usually emit more greenhouse gases than fossil fuels. This also applies to indirect land usage changes if existing agricultural land is used for the first time for biofuel production and, as a consequence, forested areas have to be cleared in order to maintain the existing foodstuff or animal feed production.
“On the other hand, positive effects can be achieved if energy plant cultivation increases the carbon content of the soil, for example via the cultivation of oil palms on unused grazing land in Columbia or via jatropha plantations in India and eastern Africa, making deserted land arable again. ‘Despite this, you can’t speak in general terms of Jatropha as being a ‘wonder plant’, as its ecobalance is very much dependent on the agricultural practices at the site in question and the land’s previous use’, says Zah. Each (new) biofuel must therefore be examined separately and in detail.”