Land cover changes are the main causes of carbon emissions and ecological damage, so accurate land cover data are essential for precise carbon emissions estimates. The Dempster–Shafer (D-S) evidence theory was used to fuse three sets of 30-m land cover data: China’s National Land Use and Cover Change (CNLUCC), Global 30-m Land Cover Classification with a Fine Classification System (GLC_FCS30), and the China Land Cover Dataset (CLCD), to product high-precision land cover data, and carbon emissions were calculated based on carbon emission factor method in the Yangtze River Delta (YRD) from 1990 to 2020. The results show that (1) the average annual accuracies of the three products, CNLUCC, GLC_FCS30, and CLCD, are 64%, 78%, and 76%, respectively, with CLC_FCS30 showing higher classification accuracy. (2) The D-S evidence theory as a fusion method effectively integrates multi-source land cover data, enhancing the overall accuracy of the fused data by 11% to 22% compared with the original data. (3) Carbon emissions in the YRD region reached 594.043 million tons by the end of 2020, marking an increase of 468.480 million tons since 1990. Notably, there is a significant spatial variability in carbon emissions, with coastal areas exhibiting higher emissions, and a shift toward inland regions. This can serve as a valuable reference for urban planning and environmental conservation in the YRD region.

Land use change and energy consumption caused by human activities is the primary source of carbon emissions and a driver of climate change. The study focused on the Yangtze River Delta (YRD), using the China Land Cover Dataset (CLCD) to calculate the region’s carbon emissions from 1990 to 2020. Based on the Natural Segment Method, the spatial distribution of carbon emissions in the YRD region were constructed by dividing them into three categories: heavy, medium, and light. The results indicate that: (1) Carbon emissions of the YRD region was 594.02 million tons at the end of 2020, an increase of 468.53 million tons compared with that of 1990. The impervious surface was the major source of carbon emissions, accounting for more than 98.51% of the total, and woodland was the most important carbon sink, accounting for more than 91.32% of the total carbon uptake. (2) The carbon emissions increase rate over the 30-year period has risen from rapid to gradual, with the fastest rate of increase occurring between 2000 and 2010. (3) Differences in economic development and land type lead to spatial variability in carbon emissions. Regions with substantial emissions were predominantly located in coastal areas, indicating a trend toward shifting inland. The assessment of carbon emissions is helpful for designing emissions mitigation policies.

Ecosystem services, including climate regulation and biodiversity maintenance, are vital for human well-being and sustainable development. The ecological quality evaluation system, based on the three dimensions of ecological function, ecological stability, and ecological stress, was established using the Pixel Information Expert Engine (PIE-Engine) and Moderate Resolution Imaging Spectroradiometer (MODIS) products to assess the ecological quality of the Taihu Basin from 2001 to 2020. The findings reveal that (1) the average Ecological Function Index (EFI) of the Taihu Basin showed a trend of initially decreasing and then increasing, with significant spatial differences. The highest EFI was observed in the western and southwestern regions of the Taihu Basin, which are mainly covered by forest and grassland, while the relatively lower EFI was found in the densely urbanized northeastern part of the basin. (2) The average Ecological Stability Index (ESI) of the Taihu Basin showed a similar trend to the EFI, with the rate of increase higher than the rate of decrease. The ESI was higher in the southwestern part, while in the southeastern and western parts of cropland and wetlands, the ESI was relatively low. (3) The Ecological Threat Index (ETI) of the Taihu Basin showed a fluctuating decrease followed by an increase, with the rate of increase higher than the rate of decrease. The reduction in grassland and the expansion of urban space are the main factors contributing to the increase in ecological stress. The research results of this paper will provide an important reference value for the coordinated and sustainable development of the economy and ecosystem in the Taihu Basin.