This technical report is a deliverable for the CLIMENGO project. This project is funded by the Swedish Energy Agency and is a collaboration between the Institute for Environmental Studies (IVM), Lund University, Stockholm University and the Swedish Environment Institute (SEI) in Oxford. The project aims to (1) map the institutional complexity of global energy and climate governance, (2) to evaluate its effectiveness and legitimacy, (3) and to develop a knowledge-base for decision-makers. This first technical report is written to explain the methodology for data-gathering and analysis, in relation to the first objective of CLIMENGO: mapping the institutional complexity of global energy and climate governance. For more information and access to more output of the CLIMENGO project, please visit: www.climengo.eu.