About this Methodology

This methodology concentrates only on the carbon stored in reserves and attempts to account for the primary routes in which this carbon is expected to be released into the atmosphere, both during and after production. These routes include fuel use during fuel extraction and processing; flaring, fugitive, and venting emissions; and combustion of fuel products by end consumers.

The overall goal is the availability of transparent, credible, and consistent data on potential emissions that help illuminate companies’ effects on the carbon budget and inform investment strategies and decisions to use reserves. While the methodology can be directly used by fossil fuel companies to disclose potential emissions data, other groups, such as civil society organizations, investors, and stock market listing authorities, can use the methodology indirectly to press for disclosure.

Key recommendations include the following:

• As a starting point, use the Petroleum Resource Management System (for oil and gas) and the Committee for Mineral Reserves International Reporting Standards template (for coal), or consistent national codes, to quantify the size of fossil fuel reserves.
• For oil and gas: Add in the amounts of fossil fuels used as fuel in internal operations.
• Add in the amounts of fossil fuels lost from internal operations through flaring, venting, and fugitive activities.
• Use calculation methods detailed in body of this paper to estimate the GHG emissions from fossil fuel combustion and the CH4 emissions from leakage.
• Do not account for projected carbon storage from CCS projects.
• Separately report the potential emissions from proven and probable reserves.
• Report key assumptions and the sources of emissions factors used.

If reported within a corporate GHG inventory report, potential emissions should be reported as a memo item outside of the scopes. See the GHG Protocol Corporate Accounting and Reporting Standard for further information.