The Greenhouse Gas Protocol
The Greenhouse Gas Protocol (GHG Protocol) is a widely used international accounting tool for understanding, quantifying and managing greenhouse gas emissions. The GHG Protocol was developed by the World Resources Institute and the World Business Council for Sustainable Development. The GHG Protocol defines direct and indirect emissions as follows:
Direct GHG emissions: emissions from sources that are owned or controlled by the reporting entity.
Indirect GHG emissions: emissions that are a consequence of the activities of the reporting entity, but occur at sources owned or controlled by another entity.
The GHG Protocol further groups these direct and indirect emissions into three scopes:
Scope 1: All direct GHG emissions.
Scope 2: Indirect GHG emissions from consumption of purchased electricity, heat or steam.
Scope 3: Other indirect emissions, such as the extraction and production of purchased materials and fuels, transport-related activities in vehicles not owned or controlled by the reporting entity, electricity-related activities (including transmission and distribution losses) not covered in Scope 2, outsourced activities, waste disposal and any other activities not covered in Scope 2.
The full text of the GHG Protocol can be seen here.
Other useful GHG Protocol publications can be downloaded here.