In recent decades, multimodal transportation has played a crucial role in modern logistics and transportation systems because of its high capacity and low cost. However, multimodal transportation driven mainly by fossil fuels may result in significant carbon emissions. In addition, transportation costs, transportation efficiency, and customer demand are also key factors that constrain the development of multimodal transportation. In this paper, we develop, for the first time, a many-objective multimodal transportation route optimization (MTRO) model that simultaneously considers economic cost, carbon emission cost, time cost, and customer satisfaction, and we solve it via the nondominated sorting genetic algorithm version III (NSGA-III). Second, to further improve the convergence performance, we introduce a fuzzy decision variable framework to improve the NSGA-III algorithm. This framework can reduce the search range of the optimization algorithm in the decision space and make it converge better. Finally, we conduct numerous simulation experiments on test problems to verify the applicability and superiority of the improved algorithm and apply it to MTRO problems under uncertain demand. This work fills the research gap for MTRO problems and provides guidance for relevant departments in developing transportation and decarbonization plans.

As a crucial basic natural resource, water resources are the cornerstone for sustainable national economic development. This paper takes the 2014 pilot water rights trading policy (WRT) as an entry point and uses a difference-in-differences (DID) model to test the policy effect of WRT on water-use efficiency (WUE) based on panel data for 30 Chinese provinces from 2005 to 2021. The study shows that WRT can significantly improve the regional WUE, and these results remain valid after a series of robustness tests, such as the parallel trend test, placebo test, and PSM-DID. Mechanistic analysis revealed that WRT can produce the Porter effect, which affects the WUE through technological innovation. The results of the heterogeneity analysis based on the synthetic control method (SCM) showed that WRT effectively improved WUE in Jiangxi, Henan, Ningxia, Hubei, and Guangdong, but did not achieve the expected effect in Inner Mongolia or Gansu. This paper provides solid empirical support for assessing the effectiveness of WRT and accelerating the process of establishing a unified national WRT market in China by 2025.

The dual carbon goal is a systematic project involving the entire society and has a leading and systematic role in the green and low-carbon development of China. In this study, we used the CiteSpace software to visualize and analyze 5809 documents from the core database of Web of Science from 1995 to 2023, covering four aspects: descriptive statistics, network collaboration, research hotspots, and thematic evolution analysis. The number of studies in the field of dual carbon is in an explosive growth stage and China and the Chinese Academy of Sciences have become the core country and institution for research, respectively, in this field. Major high-impact journals include Cleaner Production, Energy, Renewable and Sustainable Energy Review, Applied Energy, and Energy Policy. Relevant research has mainly focused on carbon neutralization, CO₂ emissions, impact factors, energy, and emission reduction performance. Research hotspots primarily include carbon dioxide electrocatalytic reduction technology, sustainable energy transition strategies, and green financial policy tools. The government should further support for the research and development of carbon-neutral technologies, particularly for the industrialization and application of CO₂ electrocatalytic reduction technology. Meanwhile, investment in renewable energy should be increased to optimize the energy structure and promote energy transition. In addition, green financial policy tools must be improved to promote the healthy development of the green financial market. The transparency and efficiency of the carbon trading market can be improved using digital technology and big data analysis, thus promoting the deep integration of the digital economy, with the goal of carbon neutrality.