Trade-Off Between Vegetation Co2 Sequestration And Fossil Fuel-Related Co2 Emissions: A Case Study Of The Guangdong-Hong Kong-Macao Greater Bay Area Of China

Carbon neutrality has attracted tremendous attention. Cities contribute the most to CO2 emissions. However, the contribution of vegetation to fossil-fuel-related CO2 emissions in urban agglomeration is unclear. Clarifying the trade-off role of vegetation can disaggregate carbon reduction targets down to sub-units to adapt to and even mitigate global warming. In this study, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), one of the world's largest metropolitan areas, was studied using our proposed inter-calibration method. The results showed that the inter-calibration method is satisfactory and that the EANTLI model effectively decreases the blooming and saturation effects of nighttime light. In addition, fossil-fuel-related CO2 emissions increased significantly (P < 0.0001) in the GBA during 2000-2018, while the variation in CO2 sequestrations was far lower than that in the increase in emissions. CO2 sequestrations by vegetation fully offset fossil-fuel-related CO2 emissions in 2000, while the status reversed after 2001. Our findings illustrate the role of vegetation carbon sequestration in offsetting fossil-fuel-related CO2 emissions and emphasize the importance of a CO2 budget. Additionally, the one city, one policy strategy is a good choice for further adapting to and mitigating global warming.