Across the world, human activity is approaching planetary boundaries. In northwest China, in particular, the coal industry and agriculture are competing for key limited inputs of land and water. In this situation, the traditional approach to planning the development of each sector independently fails to deliver sustainable solutions, as solutions made in sectorial ‘silos’ are often suboptimal for the entire economy. We propose a spatially detailed cost-minimizing model for coal and agricultural production in a region under constraints on land and water availability. We apply the model to the case study of Shanxi province, China. We show how such an integrated optimization, which takes maximum advantage of the spatial heterogeneity in resource abundance, could help resolve the conflicts around the water–food–energy (WFE) nexus and assist in its management. We quantify the production-possibility frontiers under different water-availability scenarios and demonstrate that in water-scarce regions, like Shanxi, the production capacity and corresponding production solutions are highly sensitive to water constraints. The shadow prices estimated in the model could be the basis for intelligent differentiated water pricing, not only to enable the water-resource transfer between agriculture and the coal industry, and across regions, but also to achieve cost-effective WFE management.

In the pursuit of China’s ambitious carbon neutrality goals, optimizing carbon-emission efficiency within the construction sector, a significant emitter, becomes critical. This study employs a super-Slacks-Based Measure (SBM) model and a Tobit regression model to analyze buildings’ heating-related carbon emissions across China, considering urban population density, electricity usage, and building energy consumption and the influencing factors that cause differences in carbon-emission efficiency difference. The results of this study show that the average building carbon-emission efficiency of 30 provinces in China is 0.789; carbon-emission efficiency is 0.89 in the south, higher than 0.69 in the north. After excluding centralized heating emissions, the value of buildings’ carbon-emission efficiency in the northern provinces increases by 0.01, of which the buildings’ carbon-emission efficiency in Jilin Province and Ningxia Hui Autonomous Region shows positive growth, respectively, by 0.12 and 0.17. In terms of influencing factors, there is a significant positive correlation between the scientific and technological levels, the regional economic scale, and carbon-emission efficiency; however, government intervention in the economy has a negative correlation with carbon-emission efficiency. Renewable energy utilization and green-policy adoption emerge as pivotal in enhancing efficiency. The contribution of this study is to underscore the necessity of fostering renewable energy, refining energy-consumption structures, and implementing green strategies to augment buildings’ heating-related carbon-emission efficiency.

With the rapid urbanization process, the construction industry has become a significant source of urban carbon emissions in China. The carbon emissions from buildings in the urban clusters of the Yangtze River Economic Belt, a crucial region for China’s economic development, have attracted considerable attention. This study focuses on urban buildings and aims to investigate the primary influencing factors of building carbon emissions in the urban clusters of the Yangtze River Economic Belt. The study highlights the innovative use of nighttime light remote sensing data to analyze urban carbon emissions and provides an in-depth exploration of the spatiotemporal characteristics of building carbon emissions in the urban clusters of the Yangtze River Economic Belt. Utilizing nighttime light remote sensing data similar to DMSP-OLS and provincial-level building carbon emissions, combined with spatial autocorrelation and spatiotemporal geographically weighted regression models, the study estimates and analyzes the building carbon emissions from 2012 to 2021 in 71 prefecture-level and above administrative regions within the three major urban clusters of the Yangtze River Economic Belt. The results indicate a continuous increase in total building carbon emissions in the three major urban clusters of the Yangtze River Economic Belt, with an accelerating growth rate. Spatially, urban building carbon emissions exhibit enhanced convergence but decreasing correlation over time, demonstrating evolving spatiotemporal patterns. Furthermore, the study identifies economic development level, population size, built-up area, and industrial structure as the main factors influencing building carbon emissions, with industrial structure showing significant impact.

External environmental changes, such as climate, industrial expansion, and population growth, threaten the sustainable development of the water–energy–food (WEF) system. Clarifying the intricate nonlinear relationships within this system and revealing the degree of coupling coordination and evolutionary trends within the WEF system can provide feasible pathways for regional sustainable development. Taking Hubei Province as the study area, this research quantified resource flows between dual systems from a resource consumption perspective. It then analyzed the temporal evolution characteristics of resource interactions within the WEF system from 2003 to 2023. In addition, this WEF system was evaluated by an evaluation index system according to the resource utilization level of the single system and the resource flow level of the dual system, and the CRITIC method was employed to assess the coordinated development of the WEF system in Hubei Province from 2003 to 2023. Finally, the coupling coordination degree for 2025 to 2040 was predicted through the grey GM (1,1) model. The results show that the comprehensive development evaluation index exhibited a trend of initial decline followed by an increase from 2003 to 2023. Among these, the water resources system demonstrated the relatively optimal comprehensive development status, while the energy system performed the worst. The WEF system remained in a high-level coupling stage, with its degree of coupling coordination showing a pattern of initial decline followed by an increase, reaching its peak in 2023 and entering a moderately coordinated stage. Within the dual-coupling systems, the water–food (WF) system achieved the highest level of coordinated development, reaching the good coordination stage. The GM (1,1) model indicates that Hubei Province’s WEF system can gradually achieve a good coordinated stage between 2024 and 2040.

To address carbon cost pressures from the CBAM and fluctuation in China’s domestic carbon-pricing mechanism, it is crucial to design a carbon quota allocation scheme for China’s steel industry that balances total quantity control and structural optimization. This study comprehensively considers the industry’s LCA and regional heterogeneity, introduces indicators related to “energy transformation contribution”, and employs the maximum deviation method and harmony allocation model to calculate and evaluate provincial quotas and their performance. Results show that: (1) Under the national total quantity control strategy, China’s steel industry carbon quota will be reduced to 1770 Mt by 2030; (2) Calculated via the maximum deviation method, the energy transformation contribution index accounts for 18.95% of the total contribution of all factors, while the LCA index accounts for 46.61%; (3) The maximum inter-provincial difference in carbon quotas reaches 175 Mt, reflecting significant heterogeneity in ecological carrying capacity, resource-allocation efficiency, and emission-reduction potential across regions. This study provides a scientific basis for optimizing China’s unified carbon-market mechanism and guiding the steel industry’s energy transition, and offers a reference for developing countries to address international carbon barriers through regionally differentiated strategies.

As critical minerals required for the production of new energy batteries, the demand forecasts and trends for Li, Co, Ni, and Mn are of crucial importance for ensuring the energy transition and China’s sustainable development. This study has developed a comprehensive analytical framework, combining dynamic material flow analysis, stock-driven forecasting, and scenario analysis to conduct a life-cycle assessment of the critical mineral resources (2010–2060). (1) Retrospective estimates show that in 2024, demand for Li, Co, Ni, and Mn reached 117 kt, 79 kt, 78 kt, and 45 kt, respectively. By 2060, the maximum demand for these minerals is projected to rise to 651 kt, 1090 kt, 1080 kt, and 757 kt, respectively. (2) Li is the mineral with the highest demand. Under different recovery scenarios, the lithium substitution rates reach 55.4%, 68.3%, and 85.3%, respectively. Given that the demand in cascade utilisation is far lower than the volume of retired new energy vehicle batteries, a cascade utilisation rate exceeding 23% would theoretically suffice to meet the entire relevant market demand. To secure the supply of critical minerals for energy batteries, this study suggests accelerating the construction of standardised recycling systems and implementing strict entry approvals to prevent overcapacity.