Carbon accounting tools : Are they fit for purpose in the context of arable farming?

The agricultural sector contributes 9% towards total UK greenhouse gas emissions and so may offer significant potential as a sector to help meet national and international emission reduction targets. In order to help farmers manage their emissions and to encourage more sustainable farming several carbon accounting tools are offered free of charge on the internet. This paper describes a short study that selected five tools suitable and compared their performance on a number of European arable farms to determine how useful they are for assisting in the development of sit specific mitigation strategies and how well they would perform within farm assurance or benchmarking schemes. The results were mixed, with some tools better designed for identifying mitigation opportunities than others. The results also showed that, quantitatively, the results are highly variable between tools and depended on the selected functional unit, this being highly important if the wider aspects of sustainability such as food security are to be considered. However, there is statistical consistency across the tools regarding the ranking order of the farms in terms of their emissions.