China's ambitious ecological red lines

China has initiated a new environmental strategy for delimiting “ecological red lines (ERL)” to balance economic growth and ecological and environmental protection in the country. This study uses the Yangtze River Economic Belt as a case study to illustrate the strategy and address the challenges of the implementation of this strategy. The paper identifies three knowledge gaps that urgently need research: key indicators to measure ERL, methods and criteria for spatial analysis and classification of ERL, and effective integration with other ecological protection policies. The study suggests four adaptive countermeasures to improve the scientific and practical implementation of the Chinese ERL policy.