Scope 1,2, and 3 emissions types

Since the introduction of climate change in the 1990s, the term ‘carbon emission reduction’ gained momentum and now has become an agenda so hot that it must be addressed by presidential candidates. In amidst of all these public discourse, however, how many of us know the scope of emissions and sources they fall under? I personally don't until two weeks ago. There are much specifications about carbon emissions that are essential to understanding the larger context of reducing and mitigating carbon footprints and the attainment of sustainable development on household, community and national levels.

At the very basic level, carbon emissions are classified into Direct and Indirect emissions. The Greenhouse Gas Protocol (GHG Protocol) defines them as follows:

Direct GHG emissions are emissions from sources that are owned or controlled by the reporting entity.

Indirect GHG emissions are emissions that are a consequence of the activities of the reporting entity, but occur at sources owned or controlled by another entity.

These direct and indirect emissions are further categorized into three broad scopes, based on sources of emissions, that help establish conceivably emissions reduction goals— Scope 1, 2 and 3 emissions type.

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 (e.g. T&D losses) not covered in Scope 2, outsourced activities, waste disposal, etc

The EAP’s Greenhouse Gas Reporting Program mandates the reporting of greenhouse gas emission data and other relevant information from large sources and suppliers in the United States. Categorizations of emissions thereafter provide guidance for these organizations on measuring their greenhouse gas emissions or carbon footprints and to help pursue emission mitigation strategies.