Identifying non-agricultural marginal lands as a route to sustainable bioenergy provision - A review and holistic definition

Concerns regarding global food security, direct or indirect land use change from bioenergy production require a better understanding of the alternative landbanks that may exist. The potential of ‘marginal’ land, whether for food or fuel production, has been the subject of much previous research but is currently compromised by the lack of a clear, globally accepted definition. A critical omission in the plethora of existing explicit or implicit definitions in use is the lack of comprehensive or consistent inclusion of non-agricultural land types, here re-defined as those now rendered unsuitable, unacceptable or permanently unavailable for food purposes. The result is variable inclusion of such land types in different areal studies, uncertainty regarding the nature of any land identified as ‘marginal’, in turn leading to inconsistent estimates of the role they could play in the provision of sustainable bioenergy.