Global consequences of the bioenergy greenhouse gas accounting error

Abstract

Like the global financial crisis, which resulted in part from misguided accounting of mortgages, global policies to expand transportation biofuels and bioelectricity reflect an accounting error. Although the carbon accounting in these policies assumes that plant growth offsets all carbon released by burning biofuels, only additional plant growth can provide an offset. Because they double count biomass and land already used by people or sequestering carbon, many policy proposals aim for bioenergy to supply 20% or more of the world's energy by 2050. That would require almost doubling the present global harvest of plants for all uses, which would likely lead to extensive deforestation and increase greenhouse gases. Fixing the accounting would focus policies on the more limited potential for truly low carbon biofuels.