With the increasingly hazardous effects of climate change on nature and humanity, a key question in social science research is how to foster climate action, ie, individual and collective behavior towards containment of negative consequences of climate change. Even political measures adopted by associations, political parties, governments, and governing coalitions, as well as by private stakeholders and companies, are decided upon by individual actors. Therefore, to understand and promote climate action, it is indispensable to shed light on the driving forces of individual behavior with a specific focus on what leads them to align their actions with the expected (positive) consequences on the environment. A key challenge is that individual behavior only limitedly follows a rational weighing of costs and benefits. Instead, deeply anchored beliefs, situational constellations, emotions, and the identification with social groups have been found to be significantly influential on individual action. This contribution presents a short review of the psychological roots of climate action and emphasizes the relevance of social identities. It thereby sets out a theoretical framework to explain climate action at the individual yet political level and provides empirical evidence for the role that social groups play in explaining and guiding climate action. The focus on social groups holds important implications for practitioners.