Where this document refers to “countries” or “governments”, it is also intended to include “regional economic organisations”, if appropriate. The paper benefited from direct funding for the work of the CCXG programme in 2013, including from Australia, the EC, Germany, Japan, Korea, the Netherlands, New Zealand, Norway, Sweden and Switzerland and the United Kingdom, and in-kind support from the OECD and the IEA. The authors also gratefully acknowledge information provided by Inka Gnittke, Eric Haxthausen, Anton Ililber, Dima Reda, Marianne Tegman, as well as presenters and delegates at the September 2013 CCXG Global Forum.