The true extent of agriculture's contribution to national greenhouse gas emissions

The agricultural sector is a significant contributor to greenhouse gas (GHG) emissions, and a growing global population means that agricultural production will remain high if food demands are to be met. Mitigation methods to reduce emissions from this sector are thus required, along with identification and quantification of emission sources, so that the agricultural community can act and measure its progress. International legislation requires the submission of annual reports quantifying GHG emissions from agriculture. The impor- tance of attributing the correct sources of emissions to the agricultural sector is clear; however the current approach taken by the IPCC, and reported to the UNFCCC, omits emissions from soils during agricultural land-use change from its agricultural inventory. This paper questions the IPCC approach, and the attribution of agricultural land-use change emissions to a separate category: ‘Land-use, Land-use change and Forestry’. Here a new approach adopted by the Scottish Government is examined, and compared to IPCC guidelines and national communications submitted to the Department of Energy and Climate Change (DECC) and the UNFCCC. The new Scottish Government approach attributes emissions from both land-use conversion and agricultural land under continuous use to the agricultural sector, in addition to those emissions from livestock and energy use on farms. The extent of emissions attributed to the agricultural sector using the Scottish Government approach is much greater than that using the other approaches-largely resulting from the inclusion of cropland conversion in the Scottish Government calculations. Attribution of these emissions to the agricultural sector gives calculated emissions of 10.63 Mt CO2eq in 2009, compared to 7.06 Mt CO2eq using the IPCC guidelines. This has implications for the agricultural community and may influence how and if they choose to act to reduce emissions. A large reduction in emissions from cropland conversion since 1990 means that total agricultural emissions in Scotland have fallen 26.64% when calculated by the Scottish Government, compared to a drop of only 19.13% reported to the UNFCCC. 2014 Elsevier Ltd. All rights reserved.