Many described the outcomes of 15th Conference of the Parties (COP15) in Copenhagen as insufficient or even disastrous. However, amid them, the agreement to provide USD 100 billion annually in climate finance by 2020 was heralded as an achievement. It is one of the few memorable positives for the 2009 conference, which failed to secure legally binding agreements on emission targets. Despite ongoing controversies surrounding the adequacy of financial support from developed countries, long-term climate finance has in fact grown and evolved over the past decade. This brief, in the year of that milestone, introduces the monetary goal’s main components, reviews theirstates of fulfilment, and provides a basis for discussing climate finance’s way forward, and upward. [...]