4.3 Positive tipping points in energy, transport and food systems

This chapter takes a closer look at sectoral systems – energy, transport, food and land use. These sectors are key to accelerating decarbonisation, reducing short-lived climate forcer (SLCF) emissions including methane emissions, and enhancing biodiversity. The Intergovernmental Panel on Climate Change (IPCC) most recent assessment report (IPCC, 2023) emphasises the need for rapid transformation in these sectoral systems. Successful mitigation pathways in the SSP scenarios require changes at least consistent with the best-case scenarios for past technological, behavioural or institutional change, and often depend on unprecedented rates of change. The feasibility of decarbonisation is shaped by barriers and enabling conditions across technological, economic, social-behavioural, political and ecological dimensions. These enabling conditions are context-dependent, but are essential prerequisites for propelling the fast technology and behavioural change required to achieve net-zero CO₂ emissions by mid-century. 

In each sectoral system, we examine existing or potential PTPs, drawing on case studies and other research. Much previous focus has been given to tipping points in the technological domain, for example the substitution of fossil fuels for renewable energy sources, or of battery electric vehicles (BEVs) for those powered by internal combustion engines (ICEs). For these PTPs, reinforcing feedbacks associated with economies of scale, learning by doing and technological reinforcement are instrumental in driving down costs of low-carbon innovations and making them attractive to users. The Breakthrough Effect report summarised 10 potential positive tipping points across high-emitting sectors, and potential super-leverage points that could trigger positive tipping cascades. This subsection does not aim to replicate that work. 

The Breakthrough Effect report and other studies have tended to focus on the mechanisms that enable low-carbon technologies to compete on economic terms, while acknowledging that important enabling conditions in other domains may also need to be satisfied. In reality, positive tipping dynamics likely involve strong feedbacks between technological, behavioural, political and economic processes, all of which can be important in enabling tipping into a new regime (Geels and Ayoub, 2023). Here we take a complementary focus to consider multiple other enabling conditions including, for example, how norms and behaviours or political processes can change to accelerate uptake of low-carbon technologies or other practices. 

Likewise, previous work has largely focused on supply-side substitutions for the highest-emitting technologies or industrial processes. Markets for these technologies are, of course, determined by interactions between supply and demand. Thus, to better understand the conditions in which these markets might tip into new states, we also broaden the focus to consider the role of demand-side changes in enabling positive tipping points. While supply-side substitutions can drive powerful emissions reductions, they may not be sufficient, or efficient enough on their own, to meet climate goals. For example, cities are responsible for 70 per cent of global carbon emissions and two-thirds of energy use; thus, measures that transform energy use and transport in urban environments can have powerful mitigating effects (Winkler et al,. 2023) which reinforce efforts to decarbonise energy sources. We therefore also explore the potential for discreet PTPs in reducing or changing demand itself.

In this respect, an avoid-shift-improve (ASI) logic (Creutzig et al., 2022) is helpful in structuring actions, as the three types of action each have potential to reinforce the others by amplifying their effects. Avoiding aims at refraining from harmful activities or products – reducing unnecessary consumption, possibly by redesigning service-provisioning systems. Shifting describes a change to a less-harmful activity or product – a switch to efficient and cleaner technologies and service-provisioning systems. With improving, the product or activity becomes better in terms of environmental performance – the efficiency in an existing technology is improved. 

Arguably the greatest overall positive impact is often achieved by avoiding the activity or product in the first place, and embracing the concept of sufficiency (Princen, 2005; Newell et al., 2021; Trebeck and Williams, 2019). However, in a global political economy that prioritises consumption-based economic growth, improving and shifting actions receive the lion’s share of government and business support. Shifting tends to deliver less overall positive impact, with improving delivering the least. Hence, an inherent hierarchy within these approaches exist. While improve options are not sufficient to tip systems to a decarbonised state alone, they are an important enabler and amplifier of options that can. Any increase in efficiency reduces the need for avoid and shift activities. Similarly, smaller resource systems following avoid or shift interventions, need fewer improve actions to tip (Figure 4.3.1). 

The different approaches and related measures can and should be combined – they are not mutually exclusive. While some are characterised by individual or collective behaviour change on the demand side, others are dominated by novel technology or facilitated by revamping underlying structures of a system. Typically, avoid and shift options require larger changes in social practices and in the broader socio-technical system. Options where both behavioural and technological change is required or that require a substantial change in social and user practices are typically more difficult to realise and thus difficult as a starting point for tipping dynamics (Geels et al., 2018).

The respective roles of avoiding (sufficiency), shifting (substitution) and improving (efficiency) also depend on the relative importance of behavioural and technological changes for enabling positive tipping in a particular sector (Fesenfeld et al., 2022). For instance, the widespread adoption of more plant-based diets is likely to depend on a combination of technological and behavioural changes along food supply chains and careful sequencing and synergies between avoid, shift, and improve interventions (4.3.3)

We use this logic to describe and organise interventions in this section and use these labels.