This working paper describes the likely impacts of climate change on the commodities and natural resources that comprise the mandate of the Consultative Group on International Agricultural Research (CGIAR) and its centres. It was designed as a background document for a review carried out by the High Level Panel of Experts on Food Security and Nutrition (HLPE) on the likely effects of climate change on food security and nutrition, with a focus on the most affected and vulnerable regions and populations. The paper shows that, with few exceptions, the likely impacts of climate change on key food staples and natural resources in developing countries are not understood in any great depth. The report covers 22 agricultural commodities alongside chapters on agroforestry, forests and water resources, information on the importance of each commodity, the biological vulnerability of the commodity or natural resource, and the vulnerability of populations that depend partially or wholly resources.