The GHG Protocol (Greenhouse Gas Protocol) is a globally recognised standard for measuring and managing greenhouse gas (GHG) emissions from companies and their value chains, as well as emission reduction measures. The GHG Protocol was established in 1990 out of the need for a consistent framework for greenhouse gas reporting. Today, it collaborates with governments, industry associations, NGOs, corporations and other organisations to provide the world’s most widely used calculation guidelines for emissions. In 2016, 92% of Fortune 500 companies that responded to CDP used the GHG Protocol directly or indirectly through a program based on the GHG Protocol. In addition to companies, cities around the world also use the GHG Protocol and national emissions programmes are developed based on it.