When regulating GHG emissions at the country or product level, it is critical to determine the GHG emissions from electricity consumption. In this study, we calculated production-based and consumption-based CO2 emission intensities of electricity for the OECD (the Organisation for Economic Co-operation and Development) countries during 1990–2008. We examined the impact of annual development, allocation procedure in combined heat and power production, and electricity trade on CO2 emissions. The studied factors significantly, yet highly variably, influenced the results for many countries. The consumption-based CO2 emission intensity of electricity differed significantly from the production-based intensity for some European OECD countries such...