Feasibility of peak temperature targets in light of institutional constraints

Despite faster-than-expected progress in clean energy technology deployment, global annual CO2 emissions have increased from 2020 to 2023. The feasibility of limiting warming to 1.5 °C is therefore questioned. Here we present a model intercomparison study that accounts for emissions trends until 2023 and compares cost-effective scenarios to alternative scenarios with institutional, geophysical and technological feasibility constraints and enablers informed by previous literature. Our results show that the most ambitious mitigation trajectories with updated climate information still manage to limit peak warming to below 1.6 °C (‘low overshoot’) with around 50% likelihood. However, feasibility constraints, especially in the institutional dimension, decrease this maximum likelihood considerably to 5–45%. Accelerated energy demand transformation can reduce costs for staying below 2 °C but have only a limited impact on further increasing the likelihood of limiting warming to 1.6 °C. Our study helps to establish a new benchmark of mitigation scenarios that goes beyond the dominant cost-effective scenario design.

BERTRAM Christoph;  BRUTSCHIN Elina;  DROUET Laurent;  LUDERER Gunnar;  VAN RUIJVEN Bas;  ALELUIA REIS Lara;  BERNARDO BAPTISTA Luiz;  DE BOER Harmen-Sytze;  CUI Ryna;  DAIOGLOU Vassilis;  FOSSE Florian;  FRAGKIADAKIS Dimitris;  FRICKO Oliver;  FUJIMORI Shinichiro;  HULTMAN Nate;  IYER Gokul;  KERAMIDAS Kimon;  KREY Volker;  KRIEGLER Elmar;  LAMBOLL Robin;  MANDAROUX Rahel;  ROCHEDO Pedro;  ROGELJ Joeri;  SCHAEFFER Roberto;  SILVA HERRAN Diego;  TAGOMORI Isabela;  VAN VUUREN Detlef;  VRONTISI Zoi;  RIAHI Keywan; 

2024-07-31

NATURE PORTFOLIO

JRC138404

1758-6798 (online),   

https://www.nature.com/articles/s41558-024-02073-4,    https://publications.jrc.ec.europa.eu/repository/handle/JRC138404,   

10.1038/s41558-024-02073-4 (online),