Comments and review by OECD colleagues are much appreciated and acknowledged, including Nathalie Girouard, Tomasz Kozluk, Eva Hiibner and Michael Mullan. Members of the Network on Environment and Development Cooperation (ENVIRONET) under the OECD Development Assistance Committee (DAC) also provided substantive comments and are gratefully acknowledged, in particular Austria, Germany, Sweden, United States and the United Nations Development Programme (UNDP). Laura Jenks provided editorial support.