Climate change is the most challenging issues we are facing today. It damage the environment, presents direct harms to humankind, and undermine global growth and stability. Its resolution is paramount to ensure the perpetuation of our societies.We identify two main concerns that limit cooperation regarding climate change solutions. The first concern is represented by the social dilemma, which highlights the preference of individual interests over the common good. Self-interested behavior leads to sub-optimal overall outcomes due to externalities. In the context of climate change action, self-interested individual behavior refers to the private benefits of carbon dioxide-emitting activities, while externalities refer to the impact of these polluting activities on the population as a whole. The second concern is represented by the inequality and heterogeneity of our world. Each region is subject to different levels of potential damage from climate change, and is responsible to different degrees for past and present polluting activities. Inequality exacerbate the social dilemma by bringing into play the concepts of fairness, justice and heterogeneity.Our commitment to contributing to climate change mitigation will lead us to explore social norms, belief-based mechanisms for strengthening cooperation to overcome social dilemma in contexts of inequality. We investigate the role of social norm beliefs as an equilibrium selection mechanism, as well as how they can be used to reinforce pro-social and pro-environmental behaviors. Social norms are composed of descriptive and normative beliefs that influence behavior. However, they can be subject to misconceptions leading to impoverished cooperation. We will provide answers to the followings research questions. First, how do social norms beliefs respond to inequalities and communication mechanisms. Second, how these mechanisms impact the relation between norms and pro-social and pro-environmental behavior. Third, can we represent social norms in individual decision making. Four, how can social norms be used to promote pro-environmental behavior.To answer these questions, we implemented two complementary methodologies. Using three experiments based on behavioral and experimental economics, we investigate the role and impact of social norms on human behavior. Using an ecological feedback model, we model pro-environmental behaviors in a social-ecological system.Our contribution to the understanding of how social norms shape behavior are the following:Firstly, we show how beliefs about social norms of cooperation vary across contexts and time. The mere presence of inequality in the environment causes an initial drop in normative and descriptive beliefs. Furthermore, while normative and descriptive beliefs tend to decline over time, a simple on-shot free communication support them.Secondly, we have produced evidence on how social norms influence decision-making. We show that social norms' belief impact both direct and strategic decision making, although strategic decisions are less affected. More importantly, our investigation of unequal and heterogeneous frameworks showed that normative beliefs importance was similar to descriptive beliefs in the case of heterogeneity. Together, social norm beliefs can be seen as an equilibrium selection mechanism for achieving virtuous equilibria, even in the presence of inequality and heterogeneity.Finally, we demonstrate how social norms can be used to induce behavioral change. We show three ways of using social norm information to improve pro-social and pro-environmental behavior. First, by revealing the real value of social norms, leading to a revision of beliefs in the right direction. Second, by focusing attention on a particular population to highlight the right behaviors. Third, by deploying targeted information policies to influence marginal behaviors through static information, and average behaviors through dynamic information.