This technical paper provides background information on the second review of the Adaptation Fund. The objective of the second review is to ensure the effectiveness, sustainability and adequacy of the operation of the Adaptation Fund. This document covers the progress made to date and lessons learned in the operationalisation and implementation of the Adaptation Fund in terms of: (a) The provision of sustainable, predictable and adequate financial resources, including the potential diversification of revenue streams, to fund concrete adaptation projects and programmes that are country driven and based on the needs, views and priorities of eligible Parties (chapter III.A); (b) The lessons learned from the application of the access modalities of the Adaptation Fund (chapter III.B); (c) The institutional linkages and relations, as appropriate, between the Adaptation Fund and other institutions, in particular institutions under the Convention (chapter III.C); (d) The institutional arrangements for the Adaptation Fund, in particular the arrangements with the interim secretariat and the interim trustee (chapter III.D).