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).
Any phenomenon that can be causally linked to a tipping point can be a trigger. This could be a deliberate social innovation, an investment or a policy intervention, strategically timed for maximum leverage or impact, and in awareness of the proximity of a tipping point thanks to early opportunity indicators (4.4.5). Alternatively, a trigger could be something incidental like a natural disaster or an epidemic, which causes a sudden shift in public attitudes and opens a window of opportunity for policy change. One example was the response of the German government to discontinue its nuclear power programme in the wake of the Fukushima tsunami disaster (Eder et al., 2023).
Mealy et al. (2023) argue that the most effective or ‘sensitive’ interventions should be executed when a system is close to tipping, the intervention thus acting as the decisive element or trigger. They propose a framework to help decision makers assess and prioritise interventions according to the assessment criteria, considerations and caveats presented in Table 4.2.2.
Table 4.2.2: A framework for prioritising ‘sensitive interventions’ close to a tipping point (Mealy et al., 2023).
Pillar | Key assessment elements | Other considerations and caveats |
Trigger potential | Criticality: Does the intervention exploit a system that is close to a tipping point? | Does the intervention target a critical node in a network?Is this a critical point in time? |
Barriers: Are there barriers or resistance to the intervention, and can they be easily diffused? | Who stands to lose out from the intervention?Are there any other possible stumbling blocks or binding constraints? | |
Lock-in and hysteresis: What prevents the change from being reversed? | Will a change in political leadership reverse the change?Does the intervention create path-dependency?Are actors in the system incentivised to keep the change in place? | |
Impact potential | Size of impact: Likely size of impact relative to cost of effort. | Size of impacts relative to costs can be difficult to quantify without a model that is able to capture nonlinear dynamics. However, rough estimates and expert opinion can also be useful (Lenton et al., 2008). |
Scales of impact: Potential to generate compounding change at greater scales. | Does the intervention lead to upward-scaling cascades across multiple system scales (e.g. sectors, geographies or social spheres?Does the intervention create synergies with other interventions, reinforcing the overall effect of change? | |
Speed of impact: Timescale in which the intervention can be triggered and impacts realised. | Are the desired impacts likely to be realised at a time-scale relevant to address the problem (e.g. addressing climate change requires significant emissions reductions in the next few decades) | |
Risk potential | Uncertainty: What are the sources of uncertainty around the envisioned change process and associated impacts? | Are there examples where similar interventions have been tried in the past?Are there inherent sources of uncertainty that could put the viability of the intervention at risk? |
Unintended consequences: Could the intervention lead to impacts that are not intended or anticipated? | The risk of unintended consequences can be higher in complex systems that are sensitive to small changes in initial conditions or involve complex dynamics that are not well understood. Engaging with diverse groups of stakeholders can help bring to light unapparent unintended consequences. | |
Trade-offs: Could the intervention or desired impacts cause adverse outcomes in other areas? | Are there any possibilities where the intervention or its impacts may create tensions or adverse impacts in other areas? If so, are there ways in which these trade-offs can be mitigated? |