The carbon tug-of-war: Assessing Dongjiang waterfront’s carbon neutrality potential in the battle between emissions and sinks

Urban waterfronts occupy a pivotal position in the “carbon tug-of-war”, balancing the dual challenges of rising carbon emissions and declining sink capacities. This study investigates the Dongjiang waterfront in Dongguan City to assess the spatiotemporal dynamics of carbon sources and sinks, employing the PLES (Production-Living-Ecological Spaces) framework, the STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model, grey relational analysis (GRA) method, and the GM (1,1) (Grey Model First-Order One-Variable) model. The findings reveal three key insights: (1) Shifting balance in the carbon struggle: From 2000 to 2022, carbon sink capacity declined by 47.6 %, while total emissions rose to 1.17 million tons, with per capita emissions reaching 5.30 tons, highlighting an increasing imbalance in the emissions-sink competition; (2) Nonlinear carbon sink dynamics: Contrary to a gradual decline, carbon sinks—particularly aquatic ecosystems—exhibit abrupt tipping points due to urbanization and industrial expansion. After an initial sharp drop, sink capacity temporarily stabilized before entering a phase of accelerated deterioration, reflecting intensifying ecological stress in the emissions-sinks battle; and (3) Spatial disparities & emission drivers: A significant proportion of emissions originates from urban-industrial areas, while rural areas contribute minimally to carbon sink. Key emission drivers include urbanization (+1.402 %), energy consumption (+0.095 %), and population density (+0.201 %), whereas waterfront ecological space helps mitigate emissions (−0.147 %). To address these multifaceted challenges, the study proposes the 5R framework—Reduction, Reuse, Recycling, Rethink, and Repair, integrating emissions reduction with ecological restoration as a strategy for sustainable waterfront development.