The Green Schools Alliance defines climate neutrality as having no net greenhouse gas (GHG) emissions, to be achieved by minimizing GHG emissions as much as possible through energy efficiency and conservation, then by using Renewable Energy Credits (RECs), alternative energy sources (such as wind, solar, bio-mass) and other measures to mitigate the remaining emissions.

To enable comparability and consistency in reporting, GSA Climate Pledge signatories use methodologies and/or calculators that are consistent with the standards of the Greenhouse Gas Protocol (GHG Protocol) of the World Business Council for Sustainable Development (WBCSD) and the World Resources Institute (WRI).

The GHG Protocol is the most widely used international accounting tool for quantifying GHG emissions and it provides the accounting framework for nearly every GHG standard and program in the world, including the Chicago Climate Exchange and the California Climate Action Registry.

Clean Air Cool Planet's (CACP) Campus Carbon Calculator is also consistent with GHG Protocol standards, and because it has been developed specifically for campus use, it is the tool we recommend. Currently, the standards of the GHG Protocol require institutions to include the following GHG emissions sources in their accounting: Scope 1 (direct emissions from sources owned or controlled by the institution) and Scope 2 (indirect emissions generated in purchased electricity), and are strongly encouraged to include Scope 3 (all other indirect emissions).

See Intergovernmental Panel on Climate Change.