Climate Tipping Points: Uncertainty-aware quantification of Earth system tipping potential from observations and models and assessment of associated climatic, ecological, and socioeconomic impacts

Project Information

ClimTip

Grant agreement ID: 101137601

DOI

10.3030/101137601

EC signature date 20 November 2023

Start date 1 March 2024

End date 29 February 2028

Funded under

• Climate, Energy and Mobility

Total cost

No data

EU contribution

€ 5 868 639,19

Coordinated by

TECHNISCHE UNIVERSITAET MUENCHEN
Germany

Periodic Reporting for period 1 - ClimTip (Climate Tipping Points: Uncertainty-aware quantification of Earth system tipping potential from observations and models and assessment of associated climatic, ecological, and socioeconomic impacts)

Reporting period: 2024-03-01 to 2025-08-31

Summary of the context and overall objectives of the project

Scientists suspect that some parts of the Earth system may respond to human activities in drastic, surprising and irreversible ways. The critical forcing level where such events occur are often called "tipping points" (TPs), and the involved subsystems of the Earth "tipping elements" (TEs). The likelihood of large-scale Earth system tipping events under ongoing anthropogenic forcing is highly 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 suggests decisive mitigation action, and a thorough investigation of the mechanisms, compound or cascading impacts, and the associated risks related to potential tipping events.
ClimTip aims to substantially advance our understanding of possible TEs, to identify unknown tipping events and improved early-warning signals, to quantify impacts of large-scale tipping events on the the Earth’s climate system, on ecosystems and the economy, to identify measures for improved adaptation and mitigation strategies, and to improve public knowledge and awareness of risks associated with TPs.
We provide a 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 its changes in climate and ecosystems, including early warning of forthcoming transitions.
Although Earth system models (ESMs) are the primary tool for projecting climate change, they are not yet reliable in their predictions of possible tipping events. ClimTip helps improve their representation of suggested TEs, and characterises key Earth system TEs in terms of their critical thresholds and rates, hysteresis and overshoot potential, taking into account the associated uncertainties.
As a unique climate service, ClimTip provides 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 are assessed globally and put in relation with the 2015 Paris Agreement and the EU Biodiversity Strategy 2030. ClimTip will deliver a comprehensive and precise knowledge basis for tipping-aware risk assessment and for informed adaptation and mitigation strategies. Results are disseminated to the scientific community, general public, and targeted audiences including policy makers, political activists, and the Intergovernmental Panel on Climate Change (IPCC).

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Within the first 18 project months, we have designed new methods for predicting and detecting tipping events, for calibrating climate models, and for analysing the resilience of complex systems. These theoretical developments have been designed with the ambition to develop them further into methods that can be applied to full Earth System Models (ESMs). This will allow understanding and improving ESMs and hence update our understanding of the real world.
We have run simulations with ESMs to gain understanding about the most important tipping elements: The ice sheets on Greenland and Antarctica, the Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest (ARF). These simulations are based on a new standardised experiment design. Substantial progress has been made in calibrating state-of-the-art ice sheet and ocean models to paleoclimate reconstructions, and we have initiated an analysis of the stability of the ARF.
We have also started to downscale the output of these simulations to a resolution of 15 km (regionally) and 25 km (globally), a novelty in tipping point impact research. Additionally, we have set up methodologies for assessing the impacts of tipping events on climate, ecosystems, biodiversity, agriculture, society and economy. This includes, for example, an improved crop model, and definitions and assessments of climate niches to predict shifts in the distribution of plant types and animal species. We also assess the economic impacts via damage functions proposed in the economy literature, where our novel simulations will allow separating effects of warming from impacts of tipping.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We have been disseminating results to the scientific community, general public, and targeted audiences by more than 60 published or accepted peer-reviewed scientific papers, conference contributions, policy advice for e.g. the European Commission, EU finance ministers and finance stakeholders such as MSCI, workshops with activists, monthly webinars, social media interactions, newspaper, radio, and TV interviews, and press releases for high-impact papers. Key community services by ClimTip to researchers in general are the simulation protocol to study tipping point impacts, the data from our simulations, and a list of key statements to probe the consensus amongst scientists. We also fully commit to informing international assessments, and four ClimTip PIs were recently appointed lead authors of the chapter on tipping points in WGI of the IPCC Seventh Assessment Report, AR7. As a unique climate service, ClimTip will be able to provide global high-resolution bias-corrected climate fields for large-scale tipping events based on storylines of tipping in comprehensive ESMs. The distribution and documentation of data, and the workflow for quality assessment and efficient publication have been established.
Key criteria determining further exploitation of project results will be (i) further peer-reviewed open-access publications and their scientific resonance (e.g. via citations), (ii) the ability of selected theoretical methods to be applied to complex climate models, e.g. to reveal their stability properties, (iii) the provisiopn of downscaled climate datasets by impact researchers also beyond ClimTip, and (iv) feedback of decision-makers, activists and other target groups regarding the relevance of our advice and material to improve mitigation and adaptation decisions.

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