Scientists make case for sustainable approach to bioenergy

By Susanne Retka Schill | October 26, 2012

Increasing demand for bioenergy feedstock is generating debates about food versus fuel and indirect land-use change. An interdisciplinary team of 11 scientists from seven European countries and the U.S. recently published a paper reviewing the breadth of those discussions in the international community and identifying areas in need of more research and policy development.

In an extensive review of the literature, the paper identifies the major constraints and opportunities surrounding the use of agricultural land of all classes for bioenergy production. The study, “Bioenergy from ‘surplus’ land: environmental and socio-economic implications,” was published in the open access journal BioRisk.

“We apply a critical view on this idea of targeting the cultivation of bioenergy plants on surplus land only, because environmental and socio-economic constraints which might restrict the availability and potentials of surplus land are often not taken into consideration,” the authors explain, saying there is a lack of clear definitions and unambiguous terminology, “as well as uncertainties in assessments of land availability, both on the national and the global scale, and of the potential yields of bioenergy crops when grown on surplus land.” Depending on the parameters chosen, estimates of land available for bioenergy range between 250 million hectares (620 million acres) to 1.58 billion hectares, the study points out.

“We still have limited understanding of how much land is truly surplus and suitable for energy crop production” said Jens Dauber, with the Institute of Biodiversity in Braunschweig, Germany, and the lead author of the study, “because constraints arising from environmental and socio-economic implications of bioenergy development in those areas are often not accounted for in assessments of land availability.”

The paper reviews the discussions in the literature on such issues as the classes of land considered “surplus,” nature conservation, indirect land use, water footprint, greenhouse gas emissions and loss of soil organic carbon, plus socio-economic factors.

In the final section of the paper, the authors say, “if the constraints and their implications are assessed properly and accounted for, options for sustainable bioenergy production can be identified and developed. In that case, bioenergy production might mitigate or even reverse the constraining factors in the respective areas.” The authors suggest active planning is needed to avoid potential problems from “unchecked market-driven expansion,” while outlining possible benefits from small-scale bottom-up bioenergy development. There is potential for improving rural development, the study adds, particularly in “marginal areas were local farming systems and the associated biodiversity are threatened by abandonment.” Bioenergy production could also contribute to the preservation of agricultural systems associated with high nature value, halt degradation and help to reclaim land.