Effectively managing shared natural resources is essential to protecting and improving our physical environment. This cannot be done without cooperation at international, national and local levels. Bringing together research on social dilemmas from the laboratory and the field gives us hope that we can work together to make a difference: we are social beings not ruled purely by economic motives, but influenced by our social context. Two significant insights from psychology that can help us to fight climate change are the roles of social norms and shared identities. We draw attention to...