Reducing carbon emissions and attaining sustainable economic, social, and environmental development are vital components of the 2030 Agenda for Sustainable Development. Previous research has overlooked the influence of the digital economy on urban carbon decoupling. To bridge this gap, this study employs GIS software and econometric models for analyzing the spatial distribution and characteristics of the digital economy and carbon decoupling and also investigates the direct, heterogeneous, and spatial effects of the digital economy on carbon decoupling. This study reveals: (1) A lesser digital economy presence in the northeast and northwest, while more developed in the Southeast Coast and municipalities directly under the Central Government. Cities with weak carbon decoupling are concentrated in Northeast and North China. (2) The digital economy and the decoupling of urban carbon emissions have spatial correlation and agglomeration characteristics. (3) The digital economy can contribute to decoupling carbon emissions in cities. (4) Improved urban carbon decoupling by the digital economy in central, eastern, and non-resource-based cities. (5) Spatial spillover effect in urban carbon emissions decoupling, yet the digital economy worsens nearby cities’ carbon decoupling due to a siphon effect. That research indicates that the digital economy holds significant promise not only in advancing human progress, bridging the digital divide, and fostering social development but also in driving the decoupling of urban carbon emissions.

The existing literature on the influencing factors of carbon emissions ignores the relationship between financial agglomeration and carbon emissions. Based on the analysis of the emission reduction history of major countries, this paper mainly uses the provincial-level data of China from 2002 to 2018 to explore the impact of financial agglomeration on carbon emissions. The conclusions are as follows: (1) China lacks carbon tax policies; there are many drawbacks in the carbon trading market, and a “bottom-up” voluntary emission reduction mechanism has not been formed. (2) China’s carbon emissions and financial development are characterized by spatial agglomeration. (3) Financial agglomeration can reduce carbon emissions. In central China, the low-carbon region, and the pilot regions for carbon trading, financial agglomeration has a greater impact on reducing emissions. (4) Financial agglomeration can reduce emissions by reducing the proportion of the secondary industry and increasing the proportion of the third industry. (5) Financial agglomeration can still lower carbon emissions when the spacing effect is taken into account. Finally, according to the conclusion, this paper puts forward relevant suggestions to help China reduce carbon emissions.