Electricity is fundamental to many farm chores. In this paper quantitative indices of electrical energy use were developed which reflect direct on-farm decisions for measures that farmers can adopt to reduce their greenhouse gas (GHG) emissions. With commonly available historical agricultural records as inputs, the indices allowed extrapolation backward in time with the same analytical methods as used for current energy use estimates. Each index was derived from one or more literature sources dealing with energy use in operations associated with different farming systems. Development focused on six major Canadian farm types, including two for crop production systems and four for livestock. The scale of application is national with required inputs being populations of pigs, poultry, beef and dairy cows, and crop production for small grain cereals, grain maize and canola, and greenhouse floor area. The indices were initially compared to the 1996 Farm Energy Use Survey (FEUS) of Canada and were within 5% of the FEUS electrical energy value. The integrated index was then converted to equivalent CO2 emissions for comparison with two independent sources CO2 emissions from farm energy. It agreed more closely with the 2004 Energy Use Data Handbook from Natural Resources Canada than with the 1999 Health of our Air report by Agriculture and Agri-food Canada, but was between these two sources. The comparisons of CO2 emissions took account of energy use for household as well as farm operations. The impact of the changing share of electrical energy generated by fossil fuel, rather than by nuclear or hydro-power plants was also considered. Between 1996 and 2001 Canadian farm and household use of electrical energy resulted in GHG emissions from 1
8 to 2
4 Tg of CO2, while use for farm operations only (household excluded) remained at 1
1 Tg from the 1980s to 2001 when electrical generation by fossil fuel was fixed at 1996 levels. The integrated index is well within the required accuracy to be a useful tool for reporting on the Kyoto Protocol.