Even though people are aware of the environment for the past twenty years, there is still a frustrating paradox that both researchers and sustainability practitioners face: people say and also show care about the environment, but they very rarely or rarely act on that concern by buying eco-friendly products. This systematic literature review aims to analyze twenty peer-reviewed studies to elucidate the reasons behind the persistence of this paradox and to identify feasible solutions. Utilizing the Theory of Planned Behavior (TPB), the Value-Belief-Norm (VBN) framework, and Social Identity Theory (SIT), the review categorizes findings are into five different interrelated themes: the attitude-behavior gap, structural and psychological obstacles towards green consumption, the detrimental impact of greenwashing on consumers trust, the function of eco-labels and certifications in informing purchasing decisions, and the effect of social norms and digital peer contexts on pro-environmental behavior. The literature review concludes that the disparity between the green intention ((willingness towards spending money to buy the product, but which does not actually translate into buying /purchasing behaviour) and the green action (actual action to buy/ purchase or get engagement with environment) is most accurately interpreted not as a deficiency in individual willpower, but as the foreseeable result of a market and social context that has yet to be structured to facilitate sustainable decisions. Price barriers, lack of needful information, distrust of institutions, and conflicts with the social norms all together make it harder to buy green products in ways that campaigns to change people's attitudes can't fix. The paper presents three novel conceptual frameworks that encapsulate essential findings and concludes with a series of pragmatic recommendations for marketers, policymakers, and prospective researchers.