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).
Droughts, floods and cyclones can destroy crops and pose severe challenges for the livelihoods of smallholder farmers in large parts of Africa, Asia and the Americas (Krishnamurthy, 2012). As global tipping points are crossed, the increase in rapid-onset hazards and sea level rise is likely to increase pulse-like migration and displacement (McLeman, 2018). There are likely to be tipping points, for instance, in terms of sea level rise or in the steadily deteriorating conditions beyond which human migration becomes inevitable, but they are little understood (Hauer et al., 2020). Climate, cryospheric and ecological tipping points could significantly accelerate the impacts of climate change and ecosystem change on human mobility by increasing the likelihood and/or accelerating when these tipping points are reached (see Chapter 2.2; Lenton, 2011). Specifically, the impacts from triggering an Earth system tipping point could catapult communities, which are already experiencing out-migration because of deteriorating conditions, straight to such a tipping point, forcing mass displacement. Of course, how vulnerabilities are distributed will also depend on the myriad social factors and the measures taken to increase resilience, to adapt and protect communities, and to manage the relocation of populations facing the impacts of breached tipping points.
The relationship between income levels and displacement is nonlinear, with large gaps for example in flood-induced displacement and immobility between high and low-income countries and high and low-income communities within countries (see case study below for a description of such dynamics during Hurricane Katrina in New Orleans). The systematic social, political and economic marginalisation of certain communities, uneven distribution of adaptive capacity and resilience, underinvestment in disaster preparedness, and degradation of land and infrastructure have rendered some communities and people more vulnerable to both displacement and immobility (Kakinuma et al., 2020; Johnson and Krishnamurthy, 2010; Hulme et al., 2008) (see Figure 2.3.3). Important gaps remain in our current understanding of adaptive capacity and resilience, and where the limits of adaptation and habitability lie (Hornton et al., 2021; Thomas et al,. 2021).