We are in a planetary emergency, with human behaviour in the service of economic growth breaching the safe limits of biodiversity loss, climate change, and pollution. This has significant costs for human health and social justice. We are also in a crisis of systems and behaviour: most people are concerned about this crisis, but do not contribute to the systems and behaviour change that is needed for a safe future. This is in part due to a crisis of imagination: The social and health co-benefits of living within planetary boundaries are clear and well-documented, but this is not communicated in the mainstream societal discourse in high-income societies. Instead, the focus is on sacrificing comfort to avert catastrophe. This does not create motivation for change. 

The motivation for change requires expecting rewarding outcomes—in other words, a better future. This should therefore be central to policy making and communication to address the planetary emergency. Using this approach, behavioural science can play at least three key roles in addressing these crises. First, behavioural scientists can help co-create visions for a better future, which can provide motivation for change. Second, they can use their expertise to help communicate these visions to engage stakeholders and grow the movement to translate it into action. Finally, behavioural scientists can help re-shape systems in such a way that behaviour in line with planetary boundaries is rewarding rather than costly. A better future is possible, and it will take a concerted effort to create it.