In terms of climate mitigation options, the theoretical potential of biomass energy with carbon capture and storage (BECCS) is substantial; introducing the prospect of negative emissions, it offers the vision of drawing atmospheric CO ₂ concentrations back down to pre-industrial levels. This paper reviews issues raised at a workshop on BECCS, convened in Scotland in late 2009. Presentations by bioenergy and CCS specialists covered topics including the climate policy rationale for BECCS, global biomass CCS potential, the UK potential for BECCS, the risk of fossil fuel lock-in via coal co-fi ring, and carbon market issues. In practice, the scale of the forestry and accessible CCS infrastructure required are among the obstacles to the large-scale deployment of BECCS in the near term. While biomass co-fi ring with coal offers an early route to BECCS, a quite substantial (>20%) biomass component may be necessary to achieve negative emissions in a co-fi red CCS system. Smaller scale BECCS, through co-location of dedicated or co-combusted biomass on fossil CCS CO ₂ transport pipeline routes, is easier to envisage and would be potentially less problematic. Hence, we judge that BECCS can, and likely will, play a role in carbon reduction, but care needs to be taken not to exaggerate its potential, given that (i) there are few studies of the cost of connecting bio-processing (combustion, gasifi cation or other) infrastructure with CO ₂ storage sites and (ii) that scenarios of global bioenergy potential remain contentious.