This paper is focused on climate-relatedinvestment in developing countries. It provides the readerwith an overview of climate-related activities, clarifiesthe terminology and discusses the sources of finance andpublic support. Section 1 gives an overview of currentinvestment in climate-related activities. Section 2 definesa typology of private sector investment according to stageof technology development and type of project/investment.Section 3 outlines the risks faced by a private investor inemerging markets, how these risks are typically mitigated,and discusses how barriers to low carbon investment canexacerbate these risks. Section 4 discusses the differenttypes of support relevant for the private sector and,building on the experience of the EBRD and IFC, the leverageassociated with the different project types and supportsources. Case studies of innovative use of concessionalfinance are also provided. Section 5, using the two mainavailable sources of information, assesses the level ofinvestment that will be required for a 2 degrees celsiuspathway and concludes with a description of the supportmechanisms that will be needed to mobilize private flows. Anannex provides a list of interesting initiatives beingimplemented by other intergovernmental organizations andagencies that also speak to improving private sectorengagement in the climate investment space.