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).
Social and behavioural change are key forces that can drive social tipping. Socio-behavioural systems encompass social norms, behaviours and lifestyles, communities and their cultures, and institutions. More than 65 per cent of global GHG emissions come directly or indirectly from household consumption (Ivanova et al., 2016). According to the IPCC, demand-side mitigation could reduce the total GHG emissions by 40-70 per cent compared to the baseline scenario emissions by 2050 (Creutzig et al., 2022). Demand-side mitigation (see Chapter 4.3) refers to changes in technology choices, consumption, behaviour, lifestyles, coupled production-consumption infrastructures and service provision (Creutzig et al., 2018).
A host of consumer behaviours have significant environmental impacts – for example, mobility choices, including decisions about whether and how often to fly; food waste; diet; and home weatherisation and electrification. However, there are other socio-behavioural changes with the potential to be highly impactful. Civic and political actions, including voting behaviours but also participation in social movements and boycotts, can have large impacts through their effects on policy and politics (4.4.2). Discussing climate change with one’s peers can increase their concern about climate change and willingness to support mitigation policies, and potentially contribute to collective action (Geiger and Swim, 2016). Finally, there are also many socially reinforced beliefs that may be important to overcome or replace in order to shift societies towards more sustainable consumption patterns (e.g. consumerism, individualism).
Research has identified the aspects of lifestyles that support limiting global warming to 1.5°C and the required demand-side mitigation measures, see Figure 4.4.1 (Akenji et al., 2021). Addressing carbon inequality is crucial though, with the richest 10 per cent globally accounting for nearly half of all CO2 emissions, indicating that significant carbon cuts must be made by affluent individuals through measures like carbon budget policies, luxury-focused carbon taxes, and the spread of sufficiency norms, especially among the wealthy (Kenner, 2019; Gössling and Humpe, 2023; Duscha et al., 2018; Rammelt et al., 2022; Oswald et al., 2023; IPCC 2023; Büchs et al., 2023; see Chapter 4.6). Social norms directly affect behaviours and lifestyles by defining what behaviours are appropriate in different contexts. What is considered appropriate is often linked to moral principles – what is considered right or wrong in a society (Buckholtz and Marois, 2012; Nyborg, 2018) – and can vary both across and within societies. People often behave according to social expectations for myriad reasons, including an intrinsic desire to belong and concerns that norm transgressions could lead to social exclusion (Constantino et al., 2022; Schneider and van der Linden, 2023). Changing norms hence translates into behavioural change by denormalising one behaviour and normalising another – e.g. denormalising investing in fossil fuel companies and normalising divestment (4.4.4).