实现碳中和目标需要中国能源环境经济系统深刻变革，并对能源-粮食-水-空气质量系统产生深远影响。识别实现碳中和所需的转型路径、评估碳中和转型与可持续发展目标间的协同与权衡、量化多维不确定性对碳中和转型的影响，对于稳步推动中国实现碳中和目标、支持中国长期可持续发展具有重要现实意义。现有研究多采用确定性模型方法，主要针对能源系统建模，对碳中和转型路径进行年尺度的研究，难以对不同转型路径下的能源系统灵活性、可持续发展目标协同和转型不确定性进行定量研究。 针对上述问题，本论文构建了亚年度级的中国碳中和转型综合评估模型体系，实现了能源、土地利用、水、空气质量模型的连接，采用多情景比较、蒙特卡洛分析等方法对中国能源-粮食-水-空气质量系统碳中和转型进行了定量研究。 基于该模型体系，研究表明：1）能源转型是中国应对气候变化的重点，能源CO2排放争取在“十五五”期间尽早达峰，2060年实现中和。一次能源供应2030年前后达峰，2060年可再生能源在一次能源供应占比达到63%，风电和光伏在发电量占比超75%，电能在终端能源消费占比达到56%。可再生能源并网带来灵活性挑战，需要电力供应侧和需求侧加强耦合与互动。储能设施将得到大规模开发，到2060年锂电池储能和抽水蓄能装机分别超过1000GWh和360GW。2）碳中和转型为应对其他环境问题提供机遇，但需要针对性措施来最大化协同。实现碳中和要求能源作物规模种植，能源作物和粮食作物的竞争可能引起粮食价格波动。通过减少食物浪费和转变膳食结构，能够大幅缓解气候行动对粮食安全的负面影响。碳中和转型大幅缓解水压力，2060年较2019年总取水量下降28%，电力部门取水量下降78%。碳中和转型使得2050年26个省区达到国家二级空气质量标准，强化末端治理措施确保全部省份满足空气质量标准，大幅缩减因大气污染造成的过早死亡人数。3）碳中和进程受多维不确定性影响，累计碳排放是影响转型路径、成本和技术选择的最重要因素。尽快行动能够更有效控制累计碳排放，为后续强化气候雄心和深度脱碳留出时间。2060年光伏和风电装机分别将达到5.6-6.8TW和2.6-3.5TW。实现碳中和2020--2060年能源供应部门需要累计50-69万亿元投资，较参考情景增加24%。尽快行动和可持续发展措施能显著增强气候行动与能源-粮食-水-空气质量系统转型的协同效应并减少潜在权衡，助力碳中和平稳实现。

Achieving carbon neutrality requires profound changes in energy-environment-economy system in China. These changes will have far-reaching implications for the energy-food-water-air quality nexus. Identifying transition pathways, assessing co-benefits and trade-offs, and quantifying the impact of uncertainty on the net-zero transition are crucial for achieving carbon neutrality and supporting sustainable development in China. Previous studies have predominantly employed deterministic modeling approaches, primarily for energy system modeling, to investigate net-zero transition pathways on an annual basis. This has rendered it challenging to conduct a quantitative analysis of energy system flexibility, SDG synergies, and transition uncertainty across different transition pathways. This thesis develops an integrated assessment model framework for China‘s net-zero transition at the sub-annual level, realizes the connection of energy, land use, water, and air quality models, and conducts a quantitative study on the net-zero transition of China‘s energy-food-water-air quality system by using multi-scenario comparisons and Monte Carlo analysis. The study based on the modeling framework conclusively demonstrates that: (1) China is taking decisive action to combat climate change by transforming its energy system. Energy-related CO2 emissions aim to peak as early as possible during the Fifteenth Five-Year Plan period, and reach net-zero CO2 by 2060. Primary energy supply peaks around 2030, and the share of renewable energy in primary energy supply reaches 63% in 2060, with wind and photovoltaic power generation accounting for 75% among electricity generation mix and electricity accounting for approximately 56% of final energy consumption. Sub-annual level simulations demonstrate that a considerable proportion of renewable energy integrated into the grid presents flexibility challenges that necessitate increased coupling and interaction between the electricity supply side and demand side. Energy storage needs to be aggressively developed to reach more than 1000GWh of lithium battery storage and more than 360GW of pumped hydro storage by 2060. (2) The net-zero transition presents opportunities to tackle other environmental challenges. Targeted policies are necessary to maximize synergies. Achieving carbon neutrality requires large-scale cultivation of energy crops. However, competition between energy crops and food crops can lead to food price volatility. To mitigate the negative impact of climate action on food security, reducing food waste and shifting healthy diets can be significantly helpful. The transition toward carbon neutrality will significantly mitigate water scarcity, with total water withdrawals expected to be reduced by 28% and water withdrawals from the power sector by 78% in 2060 compared to 2019. The net-zero transition will enable 26 provinces to meet the national secondary air quality standard by 2050. Enhanced end-of-pipe pollutant treatment measures ensure that all provinces meet the air quality standard and significantly reduce the number of premature deaths caused by air pollution. (3) Achieving carbon neutrality involves navigating multidimensional uncertainties. However, cumulative carbon emissions are the most significant factors that influence transition pathways, costs and technology choices. Prompt action can be more effective in controlling cumulative carbon emissions and allow ample time for subsequent intensification of climate ambition and deep decarbonization. By 2060, installed capacity of photovoltaic and wind power will reach 5.6-6.8TW and 2.6-3.5TW, respectively. Achieving carbon neutrality requires cumulative investment in energy supply of 50-69 trillion CNY, a 24% increase over the reference scenario. Prompt action and sustainability measures can significantly enhance synergies and reduce potential trade-offs between climate action and the transformation of energy-food-water-air quality systems, contributing to the smooth realization of carbon neutrality.