Fifth National Climate Assessment Reveals Urgent Action Needed to Reduce Greenhouse Gas Emissions

The Fifth National Climate Assessment (NCA5) was released in November 2023 by the U.S. Global Change Research Program. The Assessment evaluates the impacts of a changing climate across 10 US regions and a wide range of biodiversity and other interests, including water, forests and ecosystems, coasts and oceans, agriculture and rural communities, the built environment, energy and transportation, health and air quality, and economic and social systems. The Assessment is the fifth such report released by the US government since 2000, using science‐based data by more than a dozen US agencies and approximately 750 scientists tracking the impacts of climate change, and peer‐reviewed by the National Academies of Sciences, Engineering and Medicine (NASEM).1 The details outlined within the Assessment are not optimistic. In fact, the extensively peer‐reviewed report further quantifies the need to take immediate actions to reduce greenhouse gas (GHG) emissions into the atmosphere. Immediate actions will require both increased mitigation measures to reduce GHG emissions and adaptation measures as we attempt to live with the impacts of a changing climate.