Biofuels Carbon Time Bomb

The studies, commissioned by the BirdLife International, EEB, and T&E show that Europe has a major carbon accounting problem, threatening the credibility of two flagship EU environmental policies: the Renewable Energy Directive (RED) and the Emissions Trading Scheme.

Although under EU rules burning bioenergy is considered carbon neutral, the reports claim that scientific evidence show that the carbon costs of many bioenergy options are high.

The European Commission estimates that by 2020 bioenergy demand will need 195 Mtoe2 of biomass and that energy generation from biomass and waste will be 58 per cent of the total renewable energy produced.

The study, "Bird N., Pena N. & Zanchi J., The upfront carbon debt of bioenergy, Graz, Joanneum Research, June 2010", showed that biomass for bioenergy can have variable climate mitigation potential, depending on the timeframe considered and the source of the biomass.

"Additional logging for bioenergy can produce a decrease of the overall carbon stock in managed forests, which will significantly affect the GHG balance of the bioenergy system. In the short-medium term (20-50 years), additional felling3 could emit more carbon than a fossil-fuel system (CN<0)," says the report.

"In such a case, the biomass would only begin to produce benefits after 2-3 centuries.

Graph showing the interplay of emissions from harvesting and burning biomass versus savings from fossil fuel replacement in the case of additional felling in a typical European managed forest, with wood used to replace coal in power generation. The red line shows the evolution of the carbon neutrality factor: biomass use in this case leads to increased emissions for the first two and a half centuries. Note that in the emissions (‘green”) graph, positive values mean emissions while negative mean emission savings. Conversely, in the case of the carbon neutrality factor (‘red graph’), negative values mean net emissions while positive values mean net savings.

"Harvested residues are often discarded on the forest floor. When extracted for bioenergy, there is a loss in the amount of dead wood, litter and organic material in the soil, leading to a carbon loss. It is estimated that the GHGs are reduced by such bioenergy material in a 20-year timeframe by 60-90 % (CN=0.6-0.9) which is however still significantly different than carbon neutrality.

"Land conversion causes carbon stock changes - by removing vegetation and ploughing the soils to grow bio-energy feedstocks - leading to GHG emissions. If there is an initial carbon loss, such as conversion from a mature forest into fast growing plantations, the biomass will only produce climatic benefit after 150-200 years. However, when the carbon stock change is zero or positive, such as when cropland is converted into forest, the biomass system can be carbon neutral."

Another report, "Bergsma G. C., Croezen H. J., Otten M. B. J. & van Valkengoed M.P.J., Biofuels: indirect land use change and climate impact, Delft, CE Delft, June 2010", shows that growing biofuels on agricultural land results in the conversion of forests and other natural areas into crop land to replace the agricultural lands lost to biofuel production.

It says that the assumption that biofuels are carbon neutral is that biofuels feedstocks are carbon neutral.

However, the report says that this overlooks the fact that carbon would have been absorbed by vegetation on the land.

"This is exacerbated by the conversion of forests and other natural areas into agricultural land, leading to a reduction in its carbon stock - from forest to cornfield, for example," the report says.

"Land use changes can be both direct when a forest itself is converted to cropland for biofuels feedstocks, and indirect when current agricultural land is used for biofuels production, which means that existing crop production moves into natural areas."

Indirect Land Use Change effects can be partially mitigated by ensuring additional carbon growth, such as increasing yields or increasing productivity of abandoned or degraded lands in a sustainable way without damaging biodiversity. It can also be avoided by using waste products as biofuels where no land is required to produce it and it does not conflict with more efficient uses, such as a soil improver.

The two reports show that unless a number of urgent measures are taken, the EU's renewable energy policy, an EU flagship policy to combat climate change, is very likely to lead to an increase in carbon emissions.

"Getting the carbon accounting right is absolutely crucial. However, it is far from the full story," the report says.

"Bioenergy production can have very severe impacts on biodiversity, water and other natural resources and on vulnerable human populations.

"Comprehensive, watertight, legally binding and well implemented sustainability standards are absolutely vital in order to ensure that bio-energy can truly live up to its promise of being 'green energy'."

Further Reading

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You can view the full report by clicking here.