In the run-up to and at COP21 in December 2015, a number of developed countries and multilateral institutions made significant climate finance pledges. The outcome of COP21 further urged developed country Parties to scale up their level of financial support, with a concrete roadmap to achieve their USD 100 billion a year commitment by 2020.

Against this background, the OECD was asked to provide analytical support to the preparation by developed countries of such a roadmap. The intention of this note is, therefore, to provide an analysis of the scale of future climate finance as well as identify and discuss some key uncertainties. It sets out the resulting projections for climate finance in 2020 along with the underlying assumptions and methodologies used.