Diarmid Campbell-Lendrum is the Head of the climate change and health unit at WHO Headquarters. His training is on the ecology of infectious disease and public health, and he has worked on climate change and health for 20 years. During that time, Diarmid has played key roles in the development of the first quantitative estimates of the overall health impacts of climate change, resolutions of the World Health Assembly, the first four WHO global conferences on health and climate, and the expansion of WHO’s climate change and health programme, which has now provided direct support to over 30 low and middle income countries. Diarmid is author of over 100 journal papers, reports, and book chapters on the ecology and control of infectious disease, and on the health implications of global environmental change. He is an international Member of the US National Academy of Medicine, and a lead author of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Extreme Events, of the health chapters of the 5th and 6th IPCC Assessment reports, and of the first two health reports to the UN Climate Negotiations.