Natural climate solutions are critical ecosystem management measures to mitigate climate change. However, prioritizing places and possible actions is difficult. We will demonstrate a generalizable approach to identifying potential opportunities for natural climate solutions by creating a spatial hierarchy of landscape management constraints. Global forest carbon stocks and flux models were then used to examine forest-based natural climate solutions in the high carbon-density temperate coastal rainforests of western North America. Our results show that 13 million hectares are available for action, an area that contains 4,900 ± 640 megatonnes of carbon dioxide equivalent and represents 45 % of regional and 0.5 % of global above-ground forest carbon stocks. Based on historical trends, a 10 % reduction in average annual forest carbon loss through better forest management and protection could reduce forest carbon emissions by 9.1 megatons of carbon dioxide equivalent per year, equivalent to 5.2 % of terrestrial climate commitments by 2030, USA and Canada. Implementing natural climate solutions at scale will require collaborative planning with forest-dependent communities, industry, governments and indigenous peoples. (Colin S. Shanley, Rose A. Graves, Tanushree Biswas, more at nature.com)