4.1 Introduction

Previous sections of this report examine ‘negative’ Earth system tipping points (ESTPs) (Section 1), their impacts on human society, which could also trigger ‘negative’ social tipping points (Section 2), and governance options for avoiding or adapting to these risks (Section 3). This section investigates the opportunities for positive social tipping points, which we shorten to positive tipping points (PTPs). A PTP can be defined as a change in a system or subsystem, which becomes self-reinforcing beyond a critical threshold, and which leads to substantial, frequently abrupt and often irreversible impacts that are predominantly beneficial (Armstrong McKay et al., 2022; Milkoreit et al., 2018). As discussed briefly in Box 4.1.1 and at greater depth in Chapter 4.6, what is considered normatively ‘positive’ or beneficial, and by whom, is highly debatable. In principle, tipping points may be considered positive either: a) where they reduce the drivers of ‘negative’ Earth system impacts such as greenhouse gas emissions or deforestation, for example in a rapid shift to renewable energy or alternative food proteins (Meldrum et al., 2023); or b) where they improve the social foundations of sustainability (Rockström et al., 2023; Gupta et al., 2023; Raworth, 2017; Tàbara, 2023).

It is easy to understand why there has been such an explosion of interest in the concept of PTPs in recent years (Tàbara et al., 2018). Faced with a polycrisis of multiple, interconnected, and potentially existential, threats, they offer hope of neutralising or mitigating these threats and of creating a safer, healthier and more sustainable world for present and future generations. 

PTPs have already been crossed in sociotechnical systems in the uptake of solar and wind power, which are now doubling capacity every three and a half years (IEA et al., 2023; Nijsse et al., 2023). Sales of battery electric passenger vehicles have also crossed PTPs in leading markets such as Norway, and are fast approaching them in the rest of Europe, the US and China (Meldrum et al., 2023). Forward-thinking firms and individuals are exploiting these opportunities, often with the help of governments who alter the parameters – using incentives, direct investments, mandates, behavioural ‘nudges’, and so on – within which decisions are made. The evidence for PTPs in other human systems is less well established due to a lack of appropriate data, accepted definitions, assessment methods and case studies.

The increased interest has led to some overuse and misuse of the term (Milkoreit, 2023) and, inevitably, to contested definitions and meanings about what should be considered a normatively ‘positive’ outcome. All such claims rely on subjective judgement. There are also important ethical issues and the possibility of unintended negative consequences to be considered, as PTPs create ‘losers’ as well as ‘winners’, and costs as well as benefits (Pereira et al., 2023). These issues are explored further in Chapter 4.6. The growing risks of ESTPs and more than 30 years of inadequate climate action mean that we don’t have time for a ‘business as usual’ mentality or for the opportunity-driven, largely unforeseen, societal transformations of the past. Stoddard et al., 2021; Meadowcroft, 2016; Scoones et al., 2015; Geels, 2011

We need to move many times faster, in the context of a “rapidly closing window of opportunity to secure a liveable and sustainable future for all” (IPCC, 2023, p. 24; Sharpe, 2023). Human civilisation will fundamentally change in the coming decades. The only question is, will that change be collectively chosen by humanity in ways that maximise our wellbeing? Or will it be chosen for us, with potentially catastrophic consequences, if we continue to ignore biophysical limits and the risks of ESTPs? It is within our collective abilities to deliver a prosperous, climate-resilient future for all. But we require different priorities and strategies to those on which we previously relied. Most importantly, we need a systems-thinking approach to rapidly accelerate towards PTPs. This means:

• Simultaneously addressing social-behavioural, technological, economic and political domains (Stadelmann-Steffen et al., 2021), and looking at demand-side solutions such as changing behaviours, norms, lifestyles and provisioning systems related to consumption (Creutzig et al., 2022; Akenji et al., 2021), alongside supply-side solutions such as achieving cost parity for renewables (Meldrum et al., 2023).
• Focusing on more fundamental interventions that connect individuals and systems together and lead to systemic change of underlying socioeconomic structures – in parallel with the easier, lower-cost, ‘low-hanging fruit’ (Mealy et al., 2023; Newell et al., 2021; Chan et al., 2020; Abson et al., 2017). Examples might include: a revenue-neutral carbon fee and dividend scheme (Boyce, 2019); universal basic services as part of a social guarantee or ‘green jobs’ guarantee (Akenji et al., 2021).
• Creating synergies between human (social) capital and natural capital (Tàbara, 2023); measuring progress both in terms of reductions in negative tipping point stressors (e.g. greenhouse gas emissions, deforestation, land/soil degradation) and in terms of increases in positive social indicators such as health, food security, education, gender and socioeconomic equality (Rammelt et al., 2023). 
• Understanding that human systems are embedded within the Earth system (Figure 4.2.1). The safe operating limits of the Earth system, within which human societies have flourished for millennia, are governed by natural laws (Rockström et al., 2023; Dixson-Declève et al., 2022). Humans are immensely capable problem-solvers, but what we cannot do is adjust these laws for our political or economic convenience.

Systemic change requires us to reimagine how we eat, move, work, consume, invest, live and view the world (Tàbara and Chabay, 2013). It also requires practical changes in how we manage our lands and oceans, raise and spend public money, phase in/out affected industries and train/retrain workforces and redesign cities, energy systems and transport networks. Huge decisions need to be made about the kind of world we want to live in. They must be addressed with a clear understanding of the real risks we face, as well as the opportunities. Civil society, local communities, policymakers and businesses need to be at the heart of co-designing this better future and able to trust each other to deliver a just transition (Devine-Wright et al., 2022; Laybourn-Langton et al., 2021). Politicians need the support of a public mandate and a majority political coalition to enact policy changes (Eder et al., 2023; Willis, 2020).

PTPs therefore involve complex interconnections and opportunities for systemic change across multiple domains, sectors, disciplines and countries/jurisdictions. This section aims to highlight some of these interconnections and opportunities in contexts that will help decision makers navigate a responsible and evidence-based path through the complexities, using real-world examples and case studies. 

Chapter 4.2 presents a conceptual framework for understanding and acting on PTP opportunities, according to the latest research. Chapter 4.3 demonstrates the usefulness of this framework by applying it to the most carbon-intensive sectors of energy (4.3.1), transport and mobility (4.3.2), and food systems (4.3.3). Previous studies have investigated the rapid innovation and diffusion of technologies in these systems (Meldrum et al., 2023). We build on this work and introduce a demand-side perspective. Chapter 4.4 identifies cross-cutting enablers of PTPs that may be applied to many kinds of human systems: socio-behavioural change (4.4.1); politics (4.4.2); finance (4.4.3), digitalisation (4.4.4) and early opportunity indicators (4.4.5). Chapter 4.5 investigates positive tipping cascades. In previous sections of the report, tipping cascades referred to processes whereby one negative tipping point triggers at least one other negative tipping point, potentially leading to a large overall deterioration across multiple systems. We adapt this concept for PTPs and, again, building on previous studies, we examine the potential for using powerful interventions at specific times and places – so-called ‘super-leverage points’ (Meldrum et al., 2023) – that are capable of catalysing tipping cascades across multiple systems and domains. Finally, Chapter 4.6 considers important issues of risks, equity and justice in the governance of PTPs, with particular attention paid to the potential for PTPs to create ‘losers’ as well as ‘winners’, and to bring a degree of reflexivity and inclusivity with respect to marginalised voices.

Throughout, we give diverse examples from different regions, highlighting the need for differentiated solutions in each case; these are summarised in this table. Some technological and behavioural solutions might be more universal than others, while organisational solutions require context-specific knowledge and tailored actions. The specific scales, levels, sectors or domains in which positive tipping occurs is also addressed. We outline where opportunities to positively intervene exist. And we assess, where possible, the impediments and uncertainties involved. Our assessments are based on empirical insights and modelling studies.

When aiming to accelerate beneficial change, the avoid-shift-improveframework (Creutzig et al., 2022) is helpful in prioritising action. Each of the three types of actions can reinforce the others by amplifying their effects. Avoid aims to eliminate harmful activities or products by reducing production/consumption or by redesigning services; shift means switching to cleaner or more efficient alternatives; improve means enhancing the performance or efficiency of the same activity or product. We use the avoid-shift-improve framework throughout this section to describe and prioritise PTP interventions.