Interest and research in the use of algae for energy is growing but an analysis of the different methods for the accounting for the carbon dioxide (CO 2) emissions that result, is lacking. In this article, four accounting systems are evaluated for their completeness, simplicity, sectoral accuracy, and scale-independence. Two options under the Kyoto Protocol (KP), a value-chain (end-user responsibility) approach, and Point of Uptake and Release (POUR) are evaluated.
Algal material is used in biofuels, animal feeds, human foods, and food supplements, and a range of products such as paints, cosmetics, and plastics. There are also proposals for using algae as a soil amendment. This variety of uses for algal material together with the fact that it will probably contain carbon of fossil origin presents accounting challenges and reveals inconsistencies that have lain in the KPs treatment of biomass emissions. Furthermore, a key conclusion of the article is that neither proposed KP accounting approach for algae leads to correct accounting of emissions for all uses. Both value chain and POUR approaches more correctly and consistently account for algal emissions across uses. POUR offers the potential to provide comprehensive, consistent emission accounting across all uses of biomass, which represents a major step forward in accounting for CO 2 emissions due to use of biomass.