Scaling sustainable behaviour change means addressing politics, power and social justice to tackle the uneven distribution of responsibility and agency for climate action, within and between societies. This requires a holistic understanding of behaviour that bridges the ‘individual’ and ‘systemic’, and acknowledges the need for absolute emissions reductions, especially by high-consuming groups, and in key ‘hotspots’ of polluting activity, namely, travel, diet and housing. It counters the dominant focus on individuals and households, in favour of a differentiated, but collective approach, driven by bold climate governance and social mobilisation to reorient institutions and behaviour towards just transitions, sufficiency and wellbeing.

Sustainable behaviour change has been rising up the climate policy agenda as it becomes increasingly clear that far-reaching changes in lifestyles will be required, alongside shifts in policy, service provision and technological innovation, if we are to avoid dangerous levels of global heating. In this paper, we review different approaches to behaviour change from economics, psychology, sociology and political economy, to explore the neglected question of scalability, and identify critical points of leverage that challenge the dominant emphasis on individual responsibility. Although politically contentious and challenging to implement, in order to achieve the ambitious target of keeping warming below 1.5 degrees, we propose urgent structural interventions are necessary at all points within an ecosystem of transformation, and highlight five key spheres for action: a ‘strong’ sustainability pathway; pursuing just transitions (via changes to work, income and infrastructure); rebalancing political institutions to expand spaces for citizens vis-à-vis elite incumbents; focusing on high polluting actors and activities; and supporting social mobilisation. We call for a move away from linear and ‘shallow’ understandings of behaviour change, dominated by traditional behavioural and mainstreaming approaches, towards a ‘deep’, contextualised and dynamic view of scaling as a transformative process of multiple feedbacks and learning loops between individuals and systems, engaged in a mutually reinforcing ‘spiral of sustainability’.

Scaling behaviour change means addressing power and politics: challenging polluter elites and providing affordable and sustainable services for all.