Mitigation pathways exploring end-of-century temperature targets often entail temperature overshoot. Little is known about the additional climate risks generated by overshooting temperature. Here we assessed the benefits of limiting overshoot. We computed the probabilistic impacts for different warming targets and overshoot levels on the basis of an ensemble of integrated assessment models. We explored both physical and macroeconomic impacts, including persistent and non-persistent climate impacts. We found that temperature overshooting affects the likelihood of many critical physical impacts, such as those associated with heat extremes. Limiting overshoot reduces risk in the right tail of the distribution, in particular for low-temperature targets where larger overshoots arise as a way to lower short-term mitigation costs. We also showed how, after mid-century, overshoot leads to both higher mitigation costs and economic losses from the additional impacts. The study highlights the need to include climate risk analysis in low-carbon pathways.

探索世纪末温度目标的缓解途径通常会导致温度过冲。人们对温度过高产生的额外气候风险知之甚少。在这里，我们评估了限制超调的好处。我们根据一组综合评估模型计算了不同变暖目标和超调水平的概率影响。我们探讨了物理和宏观经济影响，包括持久性和非持久性气候影响。我们发现温度超调会影响许多关键物理影响的可能性，例如与极端高温相关的影响。限制过冲可降低分布右尾的风险，特别是对于低温目标，其中较大的过冲是降低短期缓解成本的一种方式。我们还展示了如何，世纪中叶之后，超调会导致更高的缓解成本和额外影响造成的经济损失。该研究强调了将气候风险分析纳入低碳路径的必要性。