Section 2: Tipping point impacts

Current state of knowledge

B.1. Crossing Earth system tipping points would have severe impacts on people and biodiversity. (Chapter 2.2)

B.1.1. Amazon dieback, ice sheet collapse, permafrost thawing and collapse of the AMOC have the potential for severe impacts on water, food and energy security, health, ecosystem services, communities and economies. (Chapter 2.2)

B.1.2. Amazon dieback would be a catastrophe for biodiversity, would add to global and regional warming, could put 6 million people at direct risk from extreme heat stress and cause between US$1 trillion and US$3.5 trillion in economic damages. (Chapter 2.2.3.1)

B.1.3. Antarctic ice sheet instability leading to a potential sea level rise of two metres by 2100 would expose 480 million people to annual coastal flooding events. (Chapter 2.2.2.1)

B.1.4. Permafrost thawing would add significantly to global warming, it already damages property and infrastructure, and 70% of current infrastructure in permafrost regions is in areas with high potential for thaw by 2050. (Chapter 2.2.2.4)

B.1.5. An AMOC collapse could substantially reduce crop productivity across large areas of the world, with profound implications for food security. (Chapters 2.2.4.1, 2.2.6.2)

B.2. Negative social tipping points triggered by climate change and Earth system tipping could have catastrophic impacts on human societies. (Chapter 2.3)

B.2.1. Escalating Earth system destabilisation threatens to disrupt societal cohesion, increase mental disorders and amplify radicalisation and polarisation. It has the potential to escalate violent conflicts, mass displacement and financial instability. (Chapter 2.3)

B.2.2. Negative social tipping points would hamper collective mitigation efforts and capacities to respond effectively to Earth system destabilisation, thus impeding the realisation of positive futures. (Chapter 2.3)

B.2.3. If societies fail to re-stabilise the Earth system we will not stay in a business-as-usual state. Instead, negative social tipping will bring about another social system state, likely characterised by greater authoritarianism, hostility, discord and alienation. (Chapter 2.3).

B.3. Negative social tipping points could cascade to create systemic risk. (Chapter 2.4)

B.3.1. Although empirical evidence is currently scarce, extrapolating known feedbacks in complex human-natural systems suggests that tipping points in social and natural systems could plausibly cascade, with catastrophic risks for human wellbeing. (Chapter 2.4)

B.3.2. Less is known about cascades from Earth’s tipping systems to socio-economic systems than those between Earth’s tipping systems. This is due to limited experience, and time lags between crossing Earth system tipping points and the reaction of social systems. (Chapters 2.3, 2.4)

B.3.3. Research on tipping cascades in human systems thus far has focused on accelerating mitigation action, rather than preparing for potential consequences of physical climate risks. (Chapters 2.2, 2.3, 2.4)

B.4. Early warning signals can be used to anticipate impact tipping points. (Chapter 2.5)

B.4.1. Methods used to detect tipping points and loss of resilience in Earth’s tipping systems (e.g. the Amazon rainforest) can be applied to anticipate tipping points in socio-economic impacts. (Chapter 2.5)

B.4.2. Recent applications of these methods have shown valuable early warning information of changes in food insecurity, and of land degradation in managed vegetation systems. (Chapter 2.5)

B.4.3. New datasets such as social media data and new technologies like deep learning have the potential to enhance
the ability to anticipate tipping points in socio-economic impacts. (Chapter 2.5)

Priorities to advance knowledge

B.5. Improved assessments of the impacts of Earth system tipping points and negative social tipping points are urgently needed. (Chapters 2.2, 2.3)

B.5.1. There is uneven and incomplete assessment of the impacts of Earth system tipping points on people, social systems and ecosystems, with almost no work on understanding the vast range of potential human and social impacts. (Chapters 2.2, 2.3)

B.5.2. Existing assessments of the economic impacts of crossing Earth system tipping points often systematically underestimate the risks. (Chapters 2.2, 2.3)

B.5.3. Assessments need to go beyond economic damages to broader human, social and cultural impacts of crossing Earth system tipping points. (Chapters 2.2, 2.3)

Recommendations:

B.5.4. Research funders should invest in improving assessment of the impacts of Earth system tipping points, starting with systematic application of existing Earth system models and impact models to tipping point scenarios. (Chapter 2.2)

B.5.5. Research funders and knowledge institutions should foster interdisciplinary collaboration between natural and social scientists to improve assessment of the economic, social and cultural impacts of tipping points. (Chapters 2.2, 2.3)

B.6. Assessment of the interactions of impact tipping points and possible cascades can be improved. (Chapter 2.4)

B.6.1. Knowledge of negative social tipping points and their impacts needs to be coupled to knowledge of Earth system tipping points through the interdisciplinary consideration of potential causal chains of propagation of systemic risk. (Chapters 2.3, 2.4)

B.6.2. Focused research is needed on the mechanisms and consequences of tipping interactions, including identifying distinct feedbacks fuelled by policy, economic, financial and behavioural dynamics that can potentially lead to cascades. (Chapter 2.4)

B.6.3. Monitoring programmes are needed to systematically gather data about potential tipping point interactions over long periods of time, founded on research into which variables to monitor. (Chapter 2.4)

Recommendation:

B.6.4. Knowledge institutions and research funders should support coordinated, interdisciplinary research programms focused on building understanding of interactions between climate and social tipping points and their role in the emergence of systemic risk. (Chapter 2.4)

B.7. Improving capacity to anticipate negative tipping points can provide increased opportunity to pre-emptively adapt and reduce vulnerability to their impacts. (Chapter 2.5)

B.7.1. Existing knowledge of negative tipping points should serve as enough ‘early warning’ to motivate urgent action, but could be augmented by more formal early warning of specific Earth system tipping points (A.4) to aid impact management. (Chapter 2.5)

B.7.2. While there is considerable room for further development (A.8) it is timely for interdisciplinary research to consider how, where and when early warning systems for Earth system tipping points should be developed. (Chapter 2.5)

B.7.3. Further research is needed into early warning of negative tipping points in socio-economic systems (B.4), particularly to determine appropriate data sources, their relevant characteristics, and the types of statistics that can provide robust early warning information. (Chapter 2.5)

B.7.4. There is considerable potential for research on negative tipping points, and early warning thereof, to contribute to wider initiatives to accelerate systemic risk assessment. (Chapter 2.5)

Recommendation:

B.7.5. Knowledge institutions and research funders should invest in interdisciplinary early warning systems research to identify indicators and techniques that empower decision makers to anticipate tipping points and take preemptive, resilience-building actions. (Chapter 2.5)