减缓与适应气候变化是本世纪全球共同面临的决定性挑战之一。评估气候变化的经济影响以及量化气候变化减缓行动的经济效益，对政策决策和可持续发展极为重要。然而，由于气候系统与经济系统相互交织的复杂性，准确量化气候变化经济影响仍存在较大困难，不同方法论下的评估结果存在较大差异。除了来自气候系统、减缓路径和社会经济发展情景等预估数据的不确定性，对气候变化在生物物理上的直接影响和经济影响机理认识不足更是重要原因。气候变化直接影响评估作为先决条件和补充信息，往往缺乏对低于国家尺度的区域性特征考量；而气候变化经济影响研究仅从经济系统的单一部门进行，这不仅容易歪曲影响的空间模式、方向和程度，还忽略了跨地区、跨部门的产业关联相互作用下波及效应所产生的间接经济影响。

能源相关的碳排放是导致气候变化的主要原因，更是当前全球减排行动的关键。作为全球最大的发展中国家和最高的碳排放国，在气候变化不利影响更突出、区域经济发展不平衡不充分、高度依赖于高能耗高排放的重工业等现实背景下，“双碳”目标（力争2030年前实现碳达峰，2060年前实现碳中和）的提出为中国经济发展带来了巨大挑战。一方面气候变化升温和经济发展双重作用影响下中国未来能源需求增长趋势显著，“双碳”目标的实施路径必将直接影响传统能源需求的增长变化；另一方面能源在跨地区紧密联系的经济系统中的关键作用和在部门生产需求中的必要性更加放大了能源需求变化的间接经济影响。

间接经济影响评估不仅能提高对气候变化经济影响程度认识的全面性，更对国家减排政策决策和可持续发展指导具有重要的理论和现实意义。为此，本文开展了气候变化和“双碳”目标下中国地区能源需求的直接影响和间接经济影响研究，研究内容以理论分析的建模研究和情景分析的量化评估包括四个部分：

一、评估框架构建与建模研究：基于投入产出（IO）分析理论厘清了气候变化到能源需求再到经济系统的链式影响机制，叠加减排目标的政策影响构建了“气候变化&双碳目标—能源需求的直接影响—间接经济影响”的链式评估框架。在此框架下陆续开展了未来能源需求变化的直接影响与间接经济影响的模型构建：（i）直接影响模块为能够捕捉气候和经济空间异质性特征的区域化能源需求模型；（ii）间接经济影响模块是基于投入产出模型通过构建能源多区域投入产出表以克服能源产品价格差异影响，并考虑能源需求特征从IO模型需求端改进的适应性多区域投入产出（AMRIO）模型。

二、气候变化情景的搭建与量化评估：基于来自CMIP6气候模式和共享社会经济路径（SSPs）的未来气温、人口和GDP预估数据搭建了5种未来气候变化情景，完成了未来气候变化情景下中国分地区能源需求变化及其间接经济影响的定量化评估，明确了中国不同地区能源需求增加变化趋势，揭示了间接经济影响在总体趋势、情景间、地区间、部门间的差异。

三、碳达峰情景的搭建与量化评估：基于历史时期能耗变化趋势和未来经济发展预估数据集设计了15种可能的碳达峰情景，与5种气候变化情景进行对比分析，明确了中国为适应气候变化和为实现碳达峰目标的未来能源需求变化差距，完成了该差距下间接经济影响的量化评估，证实了在减排目标影响下中国经济发展可能面临的巨大挑战。

四、碳中和情景的搭建与量化评估：基于是否考虑中国碳中和目标的约束搭建了碳中和情景和参考情景，对比了两情景下的能源需求变化，完成了间接经济影响的量化评估，发现了碳中和情景下能源需求相对减少的潜在经济效益，剖析了地区间和部门间的差异性。

对应以上研究内容，本文的主要结论如下：

一、跨地区、跨部门产业关联下的间接经济影响评估能够有效提升气候变化经济影响研究的全面性，其作为关键指标理应得到更广泛的关注。原因如下：

其一，间接经济影响对直接影响的放大效应显著，且以GDP量化的间接经济影响比以物理量量化的直接影响更能凸显气候变化影响能源需求结果的严峻性。未来中国地区能源需求在气候变化直接影响下增加趋势显著，2050年将增加38.9%，但增加的能源需求量因产业关联的间接经济影响显示出的负向损害效应累计至2050年将超过2017年GDP（GDP₂₀₁₇）的一半。

其二，分地区的间接经济影响能捕捉到因直接影响不显著而忽略的地区，减少了对气候变化影响空间模式认识的偏差。区间差异显示未来能源需求增加量在西北地区更突出，2050年将超过该地区当前能源使用量的2倍，而间接经济影响呈现出在整个北方地区均更加严峻的负向损害效应，累计至2050年西北、华北和东北地区将分别达到各地区GDP₂₀₁₇的129.3%、73.4%和55.2%。

其三，分部门的间接经济影响更是对气候变化直接影响的重要补充，有效避免了仅从单一部门认识气候变化影响而得出较乐观的结论。工业部门对间接经济影响的贡献度更高，所有地区均超过的20%，其次是农业、交通运输仓储邮政业、批发零售和住宿餐饮业三个部门，尤其突出的是北方地区的农业部门。

其四，间接经济影响揭示了气候变化减缓行动的潜在经济获益效应。不同气候变化情景的间接经济影响表明低排放可持续发展（SSP1_26）更能满足国家经济环境发展的目的，其间接经济影响的负向损害效应比其他情景相对减少了22.9%。

二、因实现减排目标而限制为适应气候变化将显著增加的传统能源需求，这将意味着赖以传统能源为主支撑的中国经济发展将受到威胁。

极端假设下的碳达峰情景分析显示，2030年的能源需求增量对比气候变化情景的增量将减少约42.9%，该减少量相当于2017年中国水力发电量的20倍，若未得到其他产品或技术的替代，引发的间接经济影响呈现的负向损害效应将为GDP₂₀₁₇的14.9%。可见，在中国气候雄心与经济雄心面临的挑战下，清洁能源与能源技术的发展将是减排目标完成下中国经济稳步发展的重要保障。

三、气候变化影响或将加剧中国经济发展的区间不平等，但为实现“双碳”目标的减排行动可为缩小区间不平等带来机遇，合理规划区间协作是国家碳中和全面完成且保障经济发展的有效途径。

一方面，气候变化情景下间接经济影响的负向损害效应在相对人均收入较低的北方地区更突出，约为其他地区的6~7倍，而华中、华东、华南三个地区间接经济影响累计值均不超过各地区GDP₂₀₁₇的50%。另一方面，碳中和情景下能源需求相对减少的间接经济影响呈现出的正向获益效应在低等收入地区更高，低、中、高等收入地区年均获益效应分别为各省GDP的3.9%、3.1%和2.4%。因此，在衡量地区资源禀赋与经济结构特征的基础上，为减少经济发展的不利影响，对减排目标的决策规划进行因地施策非常必要。

综上，本文聚焦于气候、能源和经济三者相互作用背后的链式影响机制，基于投入产出分析理论构建了“气候变化&双碳目标—能源需求的直接影响—间接经济影响”的综合评估框架，完成了气候变化、碳达峰、碳中和等情景设计及能源需求变化的直接影响和间接经济影响的量化评估，肯定了间接经济影响作为气候变化经济影响评估关键指标的意义。尽管在情景假设的限定下评估结果存在不确定性，但结论的方向和程度对适应和减缓气候变化行动规划极具指导意义，尤其以间接经济影响在情景间、地区间、部门间的差异为中国碳中和目标的政策制定倾斜方向提供了新的科学依据。

Climate change mitigation and adaptation is one of the defining global challenges in this century. Assessing the economic impact of climate change and quantifying the economic benefits of climate change mitigation actions are essential for policy decision-making and sustainable development. However, due to the complexity of the intertwining of climate systems and economic systems, it is still difficult to accurately quantify the economic impacts of climate change, and the assessment results under different methodologies are quite different. In addition to the uncertainty of projected data from the climate system, mitigation pathways and socio-economic development scenarios, insufficient understanding of the direct biophysical and economic impact mechanisms of climate change is the main reason for the inconsistency of assessment results. Assessments of the direct impacts of climate change, as a prerequisite and supplementary information, often lack consideration of regional characteristics below the national scale. And the study of the economic impact of climate change is only carried out from a single sector of the economic system, which not only tends to distort the spatial pattern, direction and degree of impact, but also ignores the indirect economic impact caused by the ripple effect of cross-regional and cross-sectoral industrial interaction.

Energy-related carbon emissions are the main cause of climate change and are key to ongoing global efforts to reduce emissions. As the largest developing country and the highest carbon emitter, the "dual carbon goals" (Strive to achieve carbon peak before 2030 and carbon neutrality before 2060) have brought great challenges to China's economic development under the background of more prominent adverse impacts of climate change, unbalanced and insufficient regional economic development, and high dependence on heavy industry with high energy consumption and high emissions. On the one hand, under the dual effects of climate change and economic development, the growth trend of China's future energy demand is obvious, while the implementation path of the "dual carbon goal" will inevitably directly affect the growth and change of traditional energy demand. On the other hand, energy is the key to a closely linked economic system across regions and a necessary input for sectoral production, and future changes in energy demand will amplify the indirect economic impact to a greater extent.

Indirect economic impact assessment can not only improve the comprehensive understanding of the economic impact of climate change, but also have important theoretical and practical significance for national emission reduction policy decision-making and sustainable development guidance. To this end, we conduct a quantitative assessment of the direct impacts and indirect economic impacts of energy demand in China under climate change and the "dual carbon goals". The research content includes modeling research with theoretical analysis and quantitative assessment with scenario analysis:

1. Evaluation framework construction and modeling research. Based on the theory of input-output analysis, the chain impact mechanism from climate change to energy demand to economic system is clarified. Then, superimposing the policy impact of emission reduction targets, we construct a chain comprehensive assessment framework of "climate change & dual carbon goals – direct impacts on energy demand – indirect economic impacts". The evaluation framework's model consists of two key modules: (i) the Direct Impact module is a regionalized energy demand model capable of characterizing regional climatic and economic differences; (ii) The Indirect Economic Impact Module is an Adaptive Multiregional Input-Output (AMRIO) model that is improved from the demand side of the IO model by constructing energy MRIO table to overcome the impact of price differentials and taking into account energy demand characteristics.

2. Climate change scenarios construction and quantitative assessment. 5 future climate change scenarios are constructed based on future temperature, population and GDP projections from the CMIP6 climate models and Shared Socio-economic Pathways (SSPs). And then this paper completed a quantitative assessment of changes in energy demand and indirect economic impacts at the regional scale in China under future climate change scenarios. In doing so, this paper identifies trends in increasing energy demand in different regions of China, and reveals general trends in indirect economic impacts, as well as differences in scenarios, regions, and sectors.

3. Carbon peaking scenarios construction and quantitative assessment. 15 possible carbon peaking scenarios are constructed based on the trend of energy consumption in historical periods and the forecast data set of future economic development. Then, by comparing and analyzing 15 carbon peaking scenarios with 5 climate change scenarios, the study identifies the gap between China's future energy demand changes to adapt to climate change and achieve the carbon peaking goal. Finally, this paper completed a quantitative assessment of the indirect economic impact of this gap, confirming the enormous challenges that China's economic development may face under its emission reduction targets.

4. Carbon neutrality scenarios construction and quantitative assessment. A carbon neutrality scenario and a reference scenario are constructed based on whether to consider the constraints of China's carbon neutrality goal. Then, the changes of energy demand under the two scenarios are compared. Finally, by completing the quantitative assessment of indirect economic impacts, we found the potential economic benefits of the relative reduction of energy demand under the carbon neutrality scenario, and analyzed the differences between regions and sectors.

Corresponding to the above research content, the main conclusions of this paper are as follows:

1. Indirect economic impact assessment under cross-regional and cross-sectoral industry linkages can effectively improve the comprehensiveness of climate change economic impact research, and it deserves wider attention as a key indicator. The reasons for the empirical findings are as follows:

First, the indirect economic impact has a significant amplification effect on the direct impact, and the indirect economic impact quantified by GDP can better highlight the severity of the impact of climate change on energy demand than the direct impact quantified by physical quantity. In the future, China's regional energy demand will increase significantly under the direct influence of climate change, increasing by 38.9% in 2050, but the corresponding indirect economic impact shows a more severe negative damage effect, and the cumulative value by 2050 will exceed half of the GDP₂₀₁₇.

Second, the indirect economic impacts of different regions can capture areas that are ignored because the direct impacts are not significant, reducing the bias in the understanding of spatial patterns of climate change impacts. The interval difference shows that the increase in future energy demand will be more pronounced in northwest China, which will more than double the current energy use in the region by 2050. However, the indirect economic impact shows a more severe negative damage effect in the whole of northern China, which is reflected in the cumulative damage effect in northwest, north and northeast China will reach 129.3%, 73.4% and 55.2% of the GDP₂₀₁₇ of each region, respectively by 2050.

Third, the indirect economic impacts of different sectors are an important complement to the direct impact of climate change, effectively avoiding the optimistic conclusion of understanding the impacts of climate change from only a single sector. The industrial sector contributes more to indirect economic impacts, accounting for more than 20% in all regions, followed by agriculture sector, transportation, warehousing and postal services sector, wholesale retail, and accommodation catering sector, with a particular focus on the agricultural sector in the northern region.

Fourth, indirect economic impacts reveal the potential economic benefits of climate change mitigation. The indirect economic impacts of different scenarios show that low-emission sustainable development (SSP1_26) can better meet the purpose of national economic and environmental development, and the negative damage effect of indirect economic impacts is relatively reduced by 22.9% compared to other scenarios.

2. Limiting the significantly increased demand for traditional energy sources to adapt to climate change in order to meet emissions reduction targets will mean that China's economic development, which is supported by traditional energy sources, will be threatened.

The results of the carbon peak scenario show that the increase in energy demand in 2030 will be reduced by about 42.9% compared with the increase in the climate change scenario, which is equivalent to 20 times the amount of hydropower generation in China in 2017. Under extreme assumptions, if not replaced by other clean energy products or energy technologies, the indirect economic impact of this reduction would have a negative damage effect of 14.9% of GDP₂₀₁₇.It can be seen that under the challenges of China's climate ambition and economic ambition, the development of clean energy and energy technology will be an important guarantee for the steady development of China's economy under the completion of emission reduction targets.

3. The impact of climate change may exacerbate the regional inequality of China's economic development, but the emission reduction action to achieve the "dual carbon goals" can bring opportunities to narrow the regional inequality, and reasonable planning of interval cooperation is an effective way for the country to fully complete carbon neutrality and ensure economic development.

On the one hand, the negative damage effect of indirect economic impacts under climate change scenarios is more prominent in the northern regions with relatively low per capita income, about 6~7 times that of other regions, while the cumulative value of indirect economic impacts in Central, East and South China does not exceed 50% of the GDP₂₀₁₇ of each region. On the other hand, the indirect economic impact of the relative reduction of energy demand under the carbon neutrality scenario shows a positive benefit effect, which is more pronounced in low-income regions. The average annual benefit effects in low-, middle- and high-income regions will be 3.9%, 3.1%, and 2.4% of provincial GDP, respectively. Therefore, it is necessary to measure regional resource endowments and economic structural characteristics to tailor the decision-making and planning of emission reduction targets, and the term requirements can be appropriately relaxed to reduce the adverse impact of economic development.

In summary, based on the input-output analysis theory, this paper identifies the chain impact mechanism behind the interaction between climate, energy and economy, innovatively constructs a comprehensive assessment framework of "climate change & dual carbon goals – direct impact on energy demand – indirect economic impact", completes the scenario design of climate change, carbon peaking and carbon neutrality in China, and quantifies the direct impact and indirect economic impact of energy demand change, and affirms the factual basis for indirect economic impact as a key indicator of climate change economic impact assessment. Although there is uncertainty in the assessment results under the constraints of scenario assumptions, the direction and degree of the conclusions are of great guiding significance for climate change adaptation and mitigation action planning, especially the differences in indirect economic impacts between scenarios, regions and sectors, which can provide a new scientific basis for the policy formulation direction of China's carbon neutrality goal.