Competing Interests: Declaration of interests KB, SH, SC, PM, RP, RC-R, KM, JF, TR, HSW, and YS report support from the Wellcome Trust and the Oak Foundation for the Pathfinder Initiative. KB also reports support from the National Institute for Health and Care Research (NIHR) Centre on Non-communicable Diseases and Environmental Change (NIHR203247). RH reports a move of institution to the Wellcome Trust; however, their contribution to the Commission report was completed during their time at C40. SW, RG, and BA report support from the Wellcome Trust and the Oak Foundation for the Pathfinder Initiative and receiving other grants or contracts from the UK Energy Research Centre. RCH reports receiving support from the Wellcome Trust and the Oak Foundation for the Pathfinder Initiative and other grants or contracts from Fondation Botnar and Bernard van Leer Foundation; and reports receiving payment for consulting work from The Clean Air Fund and The Children's Investment Fund Foundation and payment as support for travel from Capita.org. AH reports support from the Wellcome Trust and the Oak Foundation for the Pathfinder Initiative; grants or contracts from the Wellcome Trust for other projects (Sustainable Healthy Food Systems and Complex Urban Systems for Sustainability and Health); payment from Cambridge University Press for the coauthored book Planetary Health; other financial or non-financial interests with the Wellcome Trust (Senior Advisor on Climate Change and Health); support for attending meetings and travel from WHO and Human Frontiers Science Program; and leadership or a fiduciary role in other board, society, committee, or advocacy groups (paid or unpaid) for the Cool Roofs trial steering committee, Burkina Faso/University of Heidelberg, the NIHR Clean-Air (Africa) Global Health Research Unit, the Collaboration for the Establishment of an African Population Cohort Consortium, the InterAcademy Partnership, Climate Change and Health working group, and the Academy of Medical Sciences/Royal Society working group on A healthy future—tackling climate change mitigation and human health together. All other authors declare no competing interests.