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).
As in natural systems, tipping points in human systems are prevented by dampening (or mathematically negative) feedbacks: a decrease in a variable leads to a closed loop of causal consequences that further decreases the same variable. Dampening feedbacks are system-stabilising forces. In the enabling phase, these forces – which in the case of human systems may be hegemonic political, social, discursive, economic, institutional or infrastructural – are typically still strong. They act as barriers to broader systems change. For example, in the political domain, the efforts of fossil fuel companies to obstruct, dilute, reverse or delay climate policy is well documented (Srivastav and Rafaty, 2022). In the socio-behavioural domain, a lack of trust or information, high perceived risk and uncertainty, institutional inertia, conformity, or ingrained habits may present barriers to people switching to more sustainable lifestyles (Rosenbloom et al., 2019; Constantino et al., 2022). Economic barriers to change may include high costs, supply-chain bottlenecks, or uncertainty surrounding future policy which delays new investment (Hamilton, 2009). In the technological domain, influential opposition may prevent the building of solar or wind farms. These and other forms of resistance, including system-preserving narratives based on excessive cost and over-regulation, should be expected to become more vocal and pervasive as system changes approach PTPs (Geels, 2014, Jost 2020).
A shift in the balance between dampening feedbacks (which maintain the status quo) and reinforcing feedbacks (which drive nonlinear change) can take a system out of its stable state and over a PTP, beyond which it enters an acceleration phase towards systemic transformation. Weakening the dampening (negative) feedbacks and/or strengthening the reinforcing (positive) feedbacks can bring a system closer to a PTP. The strategic sequencing of these interventions can also sometimes be important: for example, a policy process for radical change may first require a political process (4.4.2.4).
In this section of the report we focus exclusively on PTP systems. These are human (social) systems that we want to tip because this (in theory) leads to predominantly beneficial outcomes. We are not concerned with systems explored in Section 2.3 related to negative social tipping, where systemic change is unwanted because it leads to social harms such as war and social breakdown. Therefore, in this section alone, we can describe self-reinforcing feedbacks as being both normatively as well as mathematically ‘positive’. Similarly, dampening feedbacks can be described as being both normatively and mathematically ‘negative’.