Sustainable consumption is an important approach aimed at safeguarding the well-being of future generations. However, although awareness of environmental issues and positive environmental attitudes have increased, this trend has not been reflected in green purchasing behaviours to the same extent. In the consumer behavior literature, this phenomenon is referred to as the “attitude–behavior gap.”

This chapter examines the concepts of sustainable consumption, green consumers, and green purchasing behavior, and addresses the inconsistency between attitudes and behaviours from both historical and theoretical perspectives. In this context, the attitude–behavior gap is evaluated through LaPiere’s pioneering study, Wicker’s criticisms, the Theory of Reasoned Action, and the Theory of Planned Behavior. Furthermore, the concept of the “silent contradiction” in sustainable consumption is discussed, and the main factors that hinder the transformation of pro-environmental attitudes into sustainable purchasing behavior—such as price, habits, limited accessibility, lack of trust, greenwashing, and social norms—are analyzed.

In summary, the chapter demonstrates that the primary barrier to sustainable consumption is not the absence of environmental concern, but rather the individual, social, and structural constraints that make it difficult to translate such concern into action. Therefore, the development of holistic strategies aimed at bridging the attitude–behavior gap is essential for promoting sustainable consumption. It is emphasized that businesses should make green products more affordable and accessible, rebuild consumer trust by acting transparently in their environmental claims, and that public institutions should implement policies and facilitating regulations that encourage green consumption. In addition, civil society organizations, the media, and educational institutions should leverage the power of social norms to promote sustainable lifestyles more widely.