This guidance note focuses on economic analysis of greenhouse gas emissions effects of projects in the energy sector. Recommendations seek to make practices consistent across cost-benefit calculations. Reporting of emissions of energy projects outside of economic analysis uses a different point of comparison (a baseline scenario) than does economic analysis (a without project scenario). As economic analysis needs to use a consistent set of scenarios across benefit streams, the note recommends and illustrates the use of a without project scenario for calculating emissions effects in project economic analysis.