What do we know about climate finance and what are the current knowledge gaps? Further, the exact amount of financing needed to address climate change will depend on many factors, including the level of ambition of mitigation goals and adaptation objectives, and the extent to which “correct” price signals are provided (OECD 201 la). Yet there remains international debate about what role private finance should play in fulfilling those commitments and how it should be measured when assessing progress towards the climate finance goals laid out above. This report addresses questions of private climate finance throughout. How do we measure performance and in particular what (lows of capital need to be tracked to answer this question? It is useful at the outset to outline a number of key definitions for use in this report.