How certain are the climate impacts of the increasing demand for bio-transport fuels?

Published on
November 10, 2017

Biofuels are made from renewable resources (biomass) and are an alternative for fossil fuels. They are currently incorporated in regular petrol for road transport. The demand for biofuels is increasing worldwide. However, the indirect consequences of the large-scale use of these fuels can still not fully be quantified, particularly in relation to land use change and related greenhouse-gas emissions. The European Commission recently published a study that evaluates recent scientific investigation of this topic. One of the authors of this study is Berien Elbersen from Wageningen Environmental Research (Alterra).

‘We investigated 27 important studies that looked at emissions as a result of Indirect Land Use Change (ILUC). These have indicated little consistency in their findings,’ explains Elbersen. ‘This can be attributed to the fact that the most important hypotheses and explanatory factors used by these studies differ vastly. This means that the reliability of the estimations of the emissions has not been improved in recent years. Yet, most scientific observations do indicate that the use of residual materials from agriculture and forestry produces lower emissions and that it would be worthwhile to further explore the various options for and impacts of the cultivation of crops for biofuels on marginal land.’

The use of residual materials for biofuel does carry risk too however: availability is limited, as they can also be used for other applications. An increase in the demand for biofuels can lead to scarcity on the market and force up prices in other markets. Studies investigating the use of marginal land for the production of biomass for fuel have, thus far, been mostly based on hypotheses and there is little to no empirical data about the location and size of this land and any other potential uses for it. ‘The consequences of the emission of greenhouse gasses through the use of these crops on marginal land cannot be decisively concluded,’ states Elbersen. ‘There is also a need for a detailed description and mapping of land that is marginal, degraded or abandoned in Europe and in the rest of the world.’

The evaluation of studies investigating bio-transport fuels with low risk (Low ILUC) has indicated that it is unlikely that all negative effects can be prevented through the certification of these fuels. However, a ban on the conversion of land for the cultivation of crops for bio-transport fuels can still lead to an indirect shift in land use, as food production is then more likely to take place on newly reclaimed land while the cultivation of biomass for fuel will take place on existing agricultural land. According to Elbersen, ‘It is essential that additional measures are taken, outside of the scope of certification, such as an integrated spatial planning for all land use functions, including for food production and the protection of natural vegetation.’

This study was commissioned by EC Directorate-General for Energy and conducted by a consortium of four institutes that included Wageningen Environmental Research (WENR) (in collaboration with Wageningen Economic Research [WER] and the Netherlands Environmental Assessment Agency [PBL], coordinated by the National Renewable Energy Centre [CENER] in Spain). The study can be downloaded here.