The Ningxia Hui Autonomous Region of China (Ningxia) is an important food production area in northwest China severely affected by drought. The Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were calculated based on monthly meteorological data to explore climate change and variation in drought intensity, duration, frequency, and spatial extent in Ningxia during 1972–2011. Results show that the SPEI is more applicable than the SPI for exploring climate change and drought variation in Ningxia. The Ningxia climate experienced a significant drying tendency. Annual SPEI decreased about 0.37 decade⁻¹ during 1972–2011. Drought was exacerbated by this drying tendency. Regional average duration, maximum duration, intensity, and frequency of drought identified by the SPEI increased by one month, three months, 0.15%, and 36.1%, respectively, during 1992–2011 compared to the period of 1972–1991. The spatial extent of drought identified by the SPEI increased about 14.4% decade⁻¹ in the spring during 1972–2011. Spatially, drought frequency increased from north to south. Average intensity (maximum duration) of drought calculated by the SPEI increased (decreased) northward and southward from the central arid area.

Water yield and purification are important aspects of water ecosystem services, and achieving a balanced development of the two is necessary for the development of aquatic ecosystems. Using the InVEST model, the spatiotemporal variations of regional water yield and purification services in Shanxi, China, from 2000 to 2020 were analyzed. Three future scenarios (natural development, urban development, and ecological protection) were assessed for 2030 using the PLUS model. The results showed that in 2000–2020, the water yield of Shanxi Province in terms of space was generally low in the middle and northwest and high in the southeast, and it was affected by land-use change and climatic change. From 2000 to 2020, the water yield of Shanxi Province changed by 78.8 mm. In 2030, water yield will be highest under the urban development scenario (380.53 mm) and lowest in the ecological protection scenario (368.22 mm). Moreover, the water quality purification capacity improved, with nitrogen loading high in the center and low in the east and west. Due to the implementation of environmental protection policies and the improvement of the technical level, the nitrogen load was the highest in 2000 (0.97 kg/hm²) and lowest in 2015 (0.94 kg/hm²). By 2030, because of the high nitrogen loadings of cultivation and construction land and low nitrogen loadings of forests and grasslands, the nitrogen load was lowest under the scenario of urban development (0.94 kg/hm²) and highest under ecological protection (0.85 kg/hm²).

In the context of global climate governance and China’s carbon neutrality target, Shanxi Province, one of China’s major energy exporting regions, is under high pressure to achieve carbon neutrality. This paper sets up three carbon source scenarios and three carbon sink scenarios based on the Long-range Energy Alternatives Planning System (LEAP) and CA-Markov models to simulate the future change in carbon source and carbon sink of Shanxi from 2020 to 2060; it analyzes the achievement of the carbon peaking and carbon neutrality targets for each source–sink scenario. The results show that: (1) The total energy consumption and CO₂ emissions have increased significantly, from 2000 to 2020, especially in heavy industry; (2) The CO₂ emissions are predicted to peak at 381.6 Mt, 294.1 Mt and 282.7 Mt in 2040 (baseline scenario), 2030 (policy scenario), and 2025 (carbon neutrality scenario), respectively. The achievement of the carbon neutrality mainly depends on the reduction in CO₂ emissions; (3) If Shanxi Province strives to reach the energy intensity of developed countries by 2060, with 80% of non-fossil energy generation, it has the potential to achieve the carbon neutrality target; (4) The popularization of carbon capture, utilization and storage (CCUS) technology will significantly accelerate the achievement of Shanxi Province’s carbon neutrality target.

The Yellow River Basin (YRB) faces escalating pressures from climate variability and intensive land-use change; however, how these drivers jointly shape the water ecosystem services (WES) remains insufficiently quantified. This study assessed water yield, soil conservation, and water purification capacity across the YRB from 2000 to 2020 using the InVEST model. The effects of driving forces, including climate and land-use changes, on WES were examined using scenario simulation and the geographical detector method. During 2000–2020, water yield and soil conservation displayed fluctuating upward trends, increasing by 26.24% and 30.19%, respectively, whereas nitrogen and phosphorus exports declined slightly by 4.82% and 3.08%, indicating a modest improvement in water purification. All indicators exhibited elevated values in the southeast and lower values in the northwest, with clear distinctions among the three topographic zones. The contribution rates of climate change to variations in water yield, soil conservation, nitrogen export, and phosphorus export were 97.4–99.3, 94.5–98.3, 87.2–96.0, and 85.7–95.2%, respectively, indicating the central regulatory role of climatic factors in watershed-scale water-related ecological processes. However, the contribution of land-use factors increased over time and had a significantly greater impact on water purification capacity. Distinct spatial heterogeneity was observed among the WES. Interactions among climatic, topographic, and other factors significantly enhanced the spatial variability of water yield and soil conservation services, while land-use interactions with other drivers had greater impacts on the spatial variability of water purification capacity. Thus, regionally differentiated policy strategies are essential. Our findings provide a quantitative basis for differentiating climate versus land-use interventions in water resource management and designing spatially targeted ecological restoration policies in the YRB and similar regions worldwide.