The Triptych approach is a method to share greenhouse gas emission allowances among a group of countries, based on sectoral
considerations. It has been first proposed 1997 to share the Kyoto targets for 2008 to 2012 among the EU member states. Since 1997, the methodology has been updated several times. This report provides a review of the different Triptych methodologies and describes a new update, including its application on a global level until 2050 (2100).