European countries continue to lead the world in environmental performance, according to the 2026 Environmental Performance Index (EPI), a biennial assessment produced by researchers at the Yale Center for Environmental Law & Policy and Columbia Climate School's Center for Integrated Earth System Information (CIESIN). Yet, the new assessment finds that few countries are on track to meet the global goal of net-zero greenhouse gas emissions by 2050 and that progress has slowed across a range of pollution control and natural resource management challenges.