Biofuels: network analysis of the literature reveals key environmental and economic unknowns

Abstract

Despite rapid growth in biofuel production worldwide, it is uncertain whether decision-makers possess sufficient information to fully evaluate the impacts of the industry and avoid unintended consequences. Doing so requires rigorous peer-reviewed data and analyses across the entire range of direct and indirect effects. To assess the coverage of scientific research, we analyzed over 1600 peer-reviewed articles published between 2000 and 2009 that addressed 23 biofuels-related topics within four thematic areas: environment and human well-being, economics, technology, and geography. Greenhouse gases, fuel production, and feedstock production were well-represented in the literature, while trade, biodiversity, and human health were not. Gaps were especially striking across topics in the Southern Hemisphere, where the greatest potential socio-economic benefits, as well as environmental damages, may co-occur. There was strong asymmetry in the connectedness of research topics; greenhouse gases articles were twice as often connected to other topics as biodiversity articles. This could undermine the ability of scientific and economic analyses to adequately evaluate impacts and avoid significant unintended consequences. At the least, our review suggests caution in this developing industry and the need to pursue more interdisciplinary research to assess complex trade-offs and feedbacks inherent to an industry with wide-reaching potential impacts.

Figure 1

Biofuels publishing trends by geographic region, topic and year. (A) Total numbers of articles retrieved per region. (B) Ratio of the number of articles per topic for a region to the average number of articles per topic for that region. Topics are grouped by thematic areas. EH = Environment and Human Well-being, PTI = Production-Distribution Technology and Infrastructure, EC = Economy. The dotted line indicates where topical emphasis for a region is equal to the average for that region. Numbers of articles in both panels have been adjusted by a relevancy ratio as described in the text. (C) Raw number of articles retrieved per year from 2000 to 2010, unadjusted by a relevancy ratio.

Figure 2

Network diagram showing the number of articles in common between all pairs of topics in the analysis except geographic regions. Topics are grouped by thematic areas. EH = Environment and Human Well-being, PTI = Production-Distribution Technology and Infrastructure, and EC = Economy. Numbers of articles have been adjusted by a relevancy ratio as described in the text. Line thickness indicates the categorical strength of the connection between topics.