Abstract

Mitigation pathways exploring end-of-century temperature targets entail varying degrees of temperature overshoot. The intertemporal consequences of overshoot have been typically evaluated from the point of view of mitigation.

Here, we provide the first assessment of the benefits of limiting overshoot via an ensemble of integrated assessment models. We compute physical and macroeconomic probabilistic indicators of temperature overshoot pathways for different warming targets. Temperature overshooting affects the full distribution of many critical physical impacts, such as those associated with heat extremes.
We show that limiting overshoot reduces risk in the right tail of the distribution, in particular for low-temperature targets such as 1.5C. Overshooting leads to lower short-term mitigation costs. However, our analysis allows us to fully appreciate the significant economic gains arising after 2050 from avoided impacts and reduced mitigation efforts resulting from early investments. The analysis highlights the need to integrate climate benefits in mitigation pathways and to account for fat-tailed distributions.

Dr. Laurent Drouet, Dr. Ken Oshiro, Prof. Valentina Bosetti, Dr. Keywan Riahi, Prof. Detlef van Vuuren, Prof. Massimo Tavoni, Dr. Christoph Bertram, Johannes Emmerling, Dr. Lara Aleluia Reis, Dr. Franziska Piontek, Dr. Mathijs Harmsen