Extended Reality, or XR, is a general term that combines all the advancing technologies in Virtual Reality, Augmented Reality, and Mixed Reality. The new entrant and burgeoning XR technology have been acquiring popularity around the world rapidly as a transformative one that will enable it to bring about environmental sustainability. This paper uses multi-dimensional ways for which XR proves useful in trying to address the concerns of global environmental issues that include climate change, biodiversity loss, resource depletion, and pollution. The immersive nature of XR with interactive simulations provides the opportunity to influence public attitudes and behaviours, to promote new behaviour, and to support better-informed, sustainable decision-making choices. Endangered ecosystems would be simulated for the audience to experience, first hand, the effects of environmental degradation. The virtual immersion will trigger, in part, empathy and motivation towards biodiversity conservation. XR also contributes to enhanced environmental education by providing real-time experiences and making learning about sustainability pertinent, interactive, and accessible. Beyond education and awareness, XR is more integrated into practical applications, such as urban planning, management of renewable energy sources, and circular economy models. The use of AR in smart cities optimizes infrastructure, monitors energy consumption, and minimizes waste, which would lead to greener urban environments. Industries can similarly use VR-based training in resource management in order to be efficient and promote sustainable practices for a reduced carbon footprint. This article also looks into the role of XR in supporting environmental research, where scientists can model and analyze such complex environmental systems in real-time. In this way, the researchers can forecast outcomes with a higher degree of precision in terms of prediction and give sustainability strategies with more effectiveness. This paper attests how technology from the XR is bound to exert a great impact in the progression of global objectives on sustainability. And, for such technological changes to take place, the world expects XR applications that are now existing or those innovations to be developed in the future.