Scientists have, for the first time, quantified a direct link between greenhouse gas (GHG) emissions and polar bear survival. The report “Unlock the Endangered Species Act to address GHG emissions” provides a template for estimating the demographic impact of proposed GHG-emitting actions on polar bears—overcoming a loophole in the Endangered Species Act (ESA) that has historically blocked climate considerations. The approach outlined in the paper connects the dots between greenhouse gas emissions, the number of ice-free days caused by specific amounts of emissions, and polar bear survival rates. The implications of this study go far beyond polar bears and sea ice, with the methodology applicable to other species and policy frameworks.