Early climate action is the best insurance against uncertainties in climate sensitivity and carbon dioxide removal

Researchers at the Finnish Meteorological Institute modeled cost-effective pathways to limit global warming to 1.5°C relative to the pre-industrial climate. The study focused on the interaction between the uncertainties of carbon dioxide removal and climate sensitivity. Climate sensitivity refers to how much the climate warms in response to increasing carbon dioxide concentration. Large-scale removal of carbon dioxide from the atmosphere is an essential part of the global mitigation pathways presented by the Intergovernmental Panel on Climate Change (IPCC). 

If climate sensitivity turns out to be high, meaning the climate warms significantly due to emissions, it increases the costs of mitigating climate change because emission reductions need to be faster and more extensive. One significant new result of the study was that when the uncertainty of climate sensitivity is considered, potential misjudgments in the effectiveness of carbon dioxide removal become costly. However, a strategy that relies less on uncertain future carbon dioxide removal helped to reduce the risks associated with the uncertainties of climate sensitivity and carbon dioxide removal. Previous studies have barely addressed these combined uncertainties, and cost-effective scenarios for carbon dioxide removal have been primarily based on pre-assumed certainty in climate sensitivity and the effectiveness of carbon dioxide removal.  

The new study is important for both policymakers and researchers as it emphasizes the importance of considering the uncertainties of climate sensitivity in climate change mitigation strategies. The results show that cautious assumptions about carbon dioxide removal can lead to more sustainable and cost-effective environmental policy actions. The study helps create a deeper understanding of the balance between carbon dioxide removal and emission reductions in global climate change mitigation strategies, highlighting the need for early and scientifically based actions to safeguard our planet. 

Additional information:

Researcher Theresa Schaber, Finnish Meteorological Institute, theresa.schaber@fmi.fi, tel. +358 50 535 7950

The scientific article is available on https://www.nature.com/articles/s43247-024-01456-x 

Schaber, T., Ekholm, T., Merikanto, J.et al.Prudent carbon dioxide removal strategies hedge against high climate sensitivity.Commun Earth Environ 5, 285 (2024). https://doi.org/10.1038/s43247-024-01456-x