EGU24-7633, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-7633
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
Oral | Tuesday, 16 Apr, 11:25–11:35 (CEST)
 
Room N2

Achieving net zero greenhouse gas emissions critical to limit climate tipping risks

Annika (Ernest) Högner1,2,3, Tessa Möller3,4,5, Carl-Friedrich Schleussner4,5,6, Samuel Bien1,2,3, Niklas H. Kitzmann1,3, Robin D. Lamboll7, Joeri Rogelj5,7,8, Jonathan F. Donges3,9,10, Johan Rockström2,3,9, and Nico Wunderling3,9,10
Annika (Ernest) Högner et al.
  • 1Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany
  • 2Institute of Environmental Science and Geography, University of Potsdam, Potsdam, Germany
  • 3Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany
  • 4Climate Analytics, Berlin, Germany
  • 5Energy, Climate and Environment Program, International Institute for Applied Systems Analysis, Laxenburg, Austria
  • 6Geography Department & IRI THESys, Humboldt University of Berlin, Berlin, Germany
  • 7Grantham Institute for Climate Change and the Environment, Imperial College London, London, UK
  • 8Centre for Environmental Policy, Imperial College London, London, UK
  • 9Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden
  • 10High Meadows Environmental Institute, Princeton University, Princeton, NJ, USA

Under current emission trajectories, at least temporarily overshooting the Paris global warming limit of 1.5 °C above pre-industrial levels is a distinct possibility. Permanently exceeding this limit would substantially increase the risks of triggering several climate tipping elements with associated high-end impacts on human societies and the Earth system. It is essential to assess this risk under emission pathways that temporarily overshoot 1.5 °C. Here, we investigate the tipping risks associated with a number of policy-relevant future emission scenarios, using a stylised Earth system model that comprises four interconnected core tipping elements. Assessing tipping risks in the year 2300, we find a non-linear increase for overshoots that exceed 1.8 °C peak temperature or persist above 1.5 °C beyond the end of the 21st century. Scenarios following current policies or pledges lead to high tipping risk of 30% (median) and more, with uncertainty from climate sensitivity and carbon-cycle feedbacks translating to large uncertainties in tipping risk (45% and more) for these scenarios. Further, we show that on multi-century timescales achieving and maintaining at least net-zero greenhouse gas emissions is paramount to minimise tipping risks. Our results underscore that stringent emission reductions in the current decade in line with the Paris Agreement 1.5 °C limit are critical for planetary stability.

How to cite: Högner, A. (., Möller, T., Schleussner, C.-F., Bien, S., Kitzmann, N. H., Lamboll, R. D., Rogelj, J., Donges, J. F., Rockström, J., and Wunderling, N.: Achieving net zero greenhouse gas emissions critical to limit climate tipping risks, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7633, https://doi.org/10.5194/egusphere-egu24-7633, 2024.