Rare Earth Elements are increasingly being used in a variety of emerging environmental technologies. It is therefore important to consider several interrelated issues involving the supply and demand for such materials and the relationship between them. These are complex and often not linear, requiring consideration of geostrategic as well as economic factors. The thesis examines why and how dominance of the industry shifted dramatically from the U.S. to China since the 1970s, focusing on the strategies pursued by Chinese leaders contributing to the significant migration of industries using REE along the technology supply chain to China. To gain insight into specific issues arising from the use of REE in emerging environmental technologies, the thesis teases out and scrutinizes key drivers for potential supply and demand problems, and classifies them according to three dimensions of resource scarcity to which they might contribute: physical, economic and political. It presents a table classifying key drivers for supply and demand problems involving REE according to these categories, and the potential impact of each driver: global, or on specific nations, industries, or REEs. The thesis then examines the use of REE in a specific technology: large-scale wind turbines. The thesis concludes that the development and implementation of long-term, comprehensive strategies on the national level has become increasingly necessary. If the widespread diffusion of such technologies is to be achieved, analysis along the entire material supply chain will play a crucial role in determining not only which strategies will ultimately bear fruit, but also whether the potential environmental benefits associated with these technologies will be realized. More broadly, however, the use of REE for environmental technologies illustrate increasing linkages between the use of various resources, and in this sense suggest the need for holistic policy approaches that address the underlying issues of escalating demand for energy and competing resource use.