The likelihood of large-scale Earth system tipping events under ongoing anthropogenic forcing remains uncertain. In view of the possible irreversibility associated with such events and the potentially catastrophic global consequences on climate, ecosystems, and society, the precautionary principle demands thorough investigation of the underlying mechanisms, compound or cascading impacts, and associated risks. ClimTip will substantially advance the process understanding of possible Earth system Tipping Elements (TEs). It will provide the methodological framework for characterising and constraining potential TEs from paleoclimate, observational and model data, for identifying unknown tipping potential from observations and models, and for quantifying resilience and changes thereof in climate and ecosystems, including early-warning of forthcoming transitions. Earth system models (ESMs) are the primary tool for projecting the risk of large-scale tipping events and ClimTip will substantially improve their representation of suggested TEs. This will enable the identification of safe operating spaces for a stable Earth system by characterising key Earth system TEs in terms of their critical thresholds and rates, hysteresis and overshoot potential via empirical data and ESMs, taking into account the associated uncertainties. As a unique climate service, ClimTip will provide global high-resolution bias-corrected climate fields for large-scale tipping events based on storylines of tipping in comprehensive ESMs. The associated impacts on climate, ecosystems, biodiversity, agriculture, society and economy will be assessed globally and put in relation with the Paris Agreement and the EU Biodiversity Strategy 2030. ClimTip will deliver a comprehensive and precise knowledge basis for tipping-aware risk assessment and adaptation and mitigation strategies. Results will be disseminated to the scientific community, general public, and targeted audiences including IPBES and IPCC.
There are seven main project key goals: 1) Enhance understanding of tipping phenomena in the Earth system and improve representation of key TEs in ESMs. 2) Quantify the characteristics of key TEs in terms of tipping probabilities and associated safe operating spaces, and identify unknown tipping potential 3) Determine present-day stability of climate and ecosystem TEs and establish a framework for physically based early warning of approaching regime shifts 4) Quantify impacts of large-scale tipping events across the climate system, including compounding and potential cascading effects on ecosystems, biodiversity, food security, economy and society 5) Identify measures to enhance resilience of biosphere and food supply for improved adaptation and mitigation of tipping events 6) Assess socioeconomic costs of climate and ecosystem tipping events and determine uncertainty-aware implications for climate change mitigation strategies 7) Improve public knowledge and increase awareness of associated risks associated with TPs via continuous dialogue with specific policy-relevant target groups
