The International Tourism Partnership (ITP) and the World Travel & Tourism Council (WTTC) have collaborated with 23 leading global hospitality companies to form a methodology that calculates the carbon footprint of hotel stays and meetings in a consistent and transparent way. The methodology, known as HCMI (Hotel Carbon Measurement Initiative) 1.0, was first developed in 2011 and has since been tested in hotels of different style and size in different geographical locations and refined through a stakeholder engagement process, with input from consultants KPMG. It has also been reviewed by the World Resources Institute.

The working group behind the initiative includes Accor, Beijing Tourism Group, Carlson Rezidor Hotel Group, Diamond Resorts International, Fairmont Hotels and Resorts, Hilton Worldwide, Hong Kong & Shanghai Hotels, Hyatt Corporation, InterContinental Hotels Group, Jumeirah Group, Mandarin Oriental Hotel Group, Marriott International Inc, Meliá Hotels International, MGM Resorts International, Mövenpick Hotels & Resorts, Orient-Express Hotels Ltd, Pan Pacific Hotel Group, Premier Inn - Whitbread Group, Starwood Hotels & Resorts Worldwide, Inc., Shangri-La Hotels and Resorts, the Red Carnation Hotel Collection, TUI AG, and Wyndham Worldwide.