Harmful tipping points in the natural world pose some of the gravest threats faced by humanity. Their triggering will severely damage our planet’s life-support systems and threaten the stability of our societies.
In the Summary Report:
• Narrative summary
• Global tipping points infographic
• Key messages
• Key Recommendations
Executive summary
• Section 1
• Section 2
• Section 3
• Section 4
This report is for all those concerned with tackling escalating Earth system change and mobilising transformative social change to alter that trajectory, achieve sustainability and promote social justice.
In this section:
• Foreword
• Introduction
• Key Concepts
• Approach
• References
Considers Earth system tipping points. These are reviewed and assessed across the three major domains of the cryosphere, biosphere and circulation of the oceans and atmosphere. We then consider the interactions and potential cascades of Earth system tipping points, followed by an assessment of early warning signals for Earth system tipping points.
Considers tipping point impacts. First we look at the human impacts of Earth system tipping points, then the potential couplings to negative tipping points in human systems. Next we assess the potential for cascading and compounding systemic risk, before considering the potential for early warning of impact tipping points.
Considers how to govern Earth system tipping points and their associated risks. We look at governance of mitigation, prevention and stabilisation then we focus on governance of impacts, including adaptation, vulnerability and loss and damage. Finally, we assess the need for knowledge generation at the science-policy interface.
Focuses on positive tipping points in technology, the economy and society. It provides a framework for understanding and acting on positive tipping points. We highlight illustrative case studies across energy, food and transport and mobility systems, with a focus on demand-side solutions (which have previously received limited attention).
Carbon lock-ins depend in part on and reinforce social norms linked with petrocultures (belief systems around entitlement to cheap, abundant energy provided by fossil fuels to feed consumerist lifestyles, see Wilson et al., 2017; Daggett, 2018). Decarbonisation requires disrupting carbon lock-ins and the socio-behavioural foundations that uphold them (Bernstein and Hoffmann, 2018). Such a disruption could come from the large-scale adoption of anti-fossil fuel norms, which convey the inappropriateness of behaviours that require the extraction or consumption of fossil fuels (Green, 2018; Blondeel, 2019). Social norms also affect policies, as they inform which policies are likely to have significant public support. Change in civic and political behaviour facilitates changes in policies, as politicians would be given a clear mandate for decarbonisation and regenerative policies (Stokes, 2015; Willis, 2018; see 4.4.2).
Research suggests that one important element in the social system that can tip are social norms and the behaviours, beliefs and practices they prescribe. Other elements that are important, such as social identities and values, typically change more slowly. New social norms, ideas or behaviours can spread through complex contagion processes across social networks (Guilbeault, Becker and Centola, 2018; Fink et al., 2021; Becken et al., 2021) – i.e. an individual is likely to adopt a new norm, idea or behaviour if a certain number of their peers have adopted it. Complex contagion processes can lead to social tipping (Wiedermann et al., 2020; Xie et al., 2021), including in the context of climate change (Bury et al., 2019). This means the contagion of a new norm, idea or behaviour spreads initially gradually and slowly until a critical threshold (critical number of early adopters) is reached and the contagion becomes self-reinforcing, causing transition of the social system towards a new state (a new norm, behaviour). Complex contagion is influenced by factors such as similarity of interacting individuals, the resonance of new norms with existing values and norms and the feasibility of prescribed behaviours (Guilbeault et al., 2018; Woodly, 2015; de Lanauze and Siadou-Martin, 2019; Schaumberg and Skowronek, 2022; Nyborg et al., 2016; Kaaronen and Strelkovskii, 2020). Networks characterised by clusters of strong local ties can facilitate and accelerate complex contagion (O’Sullivan et al., 2015; Centola et al., 2018).