Recent climate modeling studies have concluded that cumulative carbon emissions determine temperature increase, regardless of emission pathways. Accordingly, the optimal emission pathway can be determined from a socioeconomic standpoint. To access the path dependence of socioeconomic impacts for cumulative carbon emissions, we used a computable general equilibrium model to analyze impacts on major socioeconomic indicators on a global scale for 30–50 pathways with different emission reduction starting years, different subsequent emission pathways, and three different cumulative 2100 emission scenarios (emissions that meet the 2 °C target, the 2 °C target emissions plus 10 %, and emissions producing radiative forcing of 4.5 W/m²). The results show that even with identical cumulative emission figures, the resulting socioeconomic impacts vary by the pathway realized. For the United Nations 2 °C target, for example, (a) the 95 % confidence interval of cumulative global gross domestic product (GDP) is 1355–1363 trillion US dollars (2010–2100, discount rate = 5 %), (b) the cumulative GDP of pathways with later emission reduction starting years grows weaker (5 % significance level), and (c) emissions in 2100 have a moderate negative correlation with cumulative GDP. These results suggest that GDP loss is minimized with pathways with earlier emission reduction followed by more moderate reduction rates to achieve lower emission levels. Consequently, we suggest an early emission peak to meet the stringent target. In our model setting, it is desirable for emissions to peak by 2020 to reduce mitigation cost and by 2030 at the latest to meet the 2 °C target.

中文翻译：

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从全球社会经济角度评估固定累积二氧化碳排放的多种排放途径。

最近的气候模型研究得出结论，不管排放途径如何，累积碳排放量都会决定温度的升高。因此，可以从社会经济的角度确定最佳排放途径。为了获得社会经济影响对累积碳排放的路径依赖性，我们使用可计算的一般均衡模型来分析全球范围内对30–50条途径的主要社会经济指标的影响，这些途径有不同的减排开始年，不同的后续排放途径以及三个不同的2100个累积排放情景（满足2°C目标的排放，满足2°C目标的排放加10％，以及产生辐射强迫的排放为4.5 W / m ²）。结果表明，即使使用相同的累积排放数字，所产生的社会经济影响也会因实现的途径而异。例如，对于联合国设定的2°C目标，（a）全球累计国内生产总值（GDP）的95％置信区间为1355–1333万亿美元（2010–2100，折现率= 5％），（b ）减排开始年越晚的途径的累计GDP增长越弱（显着性水平为5％），并且（c）2100年的排放与累计GDP呈中等程度的负相关。这些结果表明，通过尽早减少排放，然后采用更适度的减少率以实现较低的排放水平，可以使GDP损失最小化。因此，我们建议尽早达到峰值以达到严格的目标。在我们的模型设置中