Dr. Renee N. Salas founded and leads the Lancet Countdown U.S. Brief Working Group, as well as contributing to the global Lancet Countdown reports. She served as the U.S. Brief lead author from 2018 to 2021, moving to senior author in 2022. Dr. Salas is an expert in the area of climate change and health and was elected to the National Academy of Medicine (NAM) in 2021 for this work. She serves on the Steering Committee for the NAM Grand Challenge on Climate Change, Health, and Equity and the Advisory Committee for The National Academies Climate Crossroads initiative. She is an emergency medicine physician at Massachusetts General Hospital and Harvard Medical School with a variety of affiliations across Harvard University.