Emission degrowth potential of Chinese city cluster toward carbon neutrality: The climate planetary boundaries perspective

The idea of downscaling the climate planetary boundaries (PBs) to national equivalents has attracted wide academic attention, but there is much less work on translating global limits to actionable and tangible city-level targets. Here we develop PBs-informed degrowth scenarios by adopting the Genuine Green Growth framework and carbon productivity indicator and applying a consumption-based multi-region input-output analysis. Results show that the top five city clusters collectively inherit a carbon emission degrowth potential of 656 Mt. by 2050. The Yangtze River Delta urban agglomeration inherits the greatest emission degrowth capacity of 252 Mt. (45 % less than that in 2017), followed by the Triangle of Central China (166 Mt). We also find carbon net flows of city clusters flow from northern and eastern coastal areas to western and southern inner lands and would decrease by nearly 48 % by 2050. Within city clusters, central cities import 4 to 16 million tons from non-central cities by 2050. Our findings highlight the dynamic fairness principle in PBs-downscaling and the importance of synergetic city-level dual‑carbon abatement roadmaps.