Assessing the Environmental Risks and Opportunities of Bioenergy Cropping

Abstract

All forms of cropping influence the environment, and bioenergy cropping is no exception. The main potential environmental benefit is the net reduction in greenhouse gas (GHG) emissions by the substitution of fossil fuels, while the main potential harm is increased pressure on land use, which can lead to competition for food production, loss of forests and the release of large amounts of carbon from soils and vegetation. The major approaches to environmental risk evaluation are experiments, environmental risk assessment, life cycle analysis, ecosystem services and post-market monitoring; while none are ideal, all these have a potential role in evaluating bioenergy cropping. Major environmental impacts vary greatly between crops, countries and management regimes. Bioenergy cropping has the most positive environmental impact when the crops are productive, have low water and nutrient requirements and can be grown on low-grade and abandoned agricultural land in arrangements that promote biodiversity. Such cropping may be able to supply around 8% of the global energy demand: bioenergy cropping should be seen as one element in a wider strategy for efficient use of land, energy, food and water.