The availability of abiotic resources is still critical to the rapidly growing human population, and rising living standards. Standard methodologies are needed to account for the depletion of resources. Some of the methods for resource depletion evaluation consider replacement of a scarce resource with an alternative resource but do not consider a time frame for the same. However, resource substitution is decided by several factors such as resource costs and price elasticity of demand, which are dynamic. Moreover, the existing methods do not consider a driving force for the replacement to occur and do not analyse the long-term consequences of resource scarcity. In this paper, a dynamic resource depletion methodology is proposed, and it has been applied to a case study of natural gas scarcity in New Zealand. A system dynamics model predicts the gas price and the rates of gas consumption over an extended period. The potential impacts are quantified using life cycle assessment (LCA) and are further aggregated into a resource depletion indicator that is based on environmental economics and decision-making perspectives for the environment. The wider economic and environmental impacts that are a result of a new chemical plant during a period of gas shortage are evaluated. With the functioning of the new plant, it was found that the rate of potential gas scarcity accelerated, leading to an increase in wider economic and environmental impacts. The discounted greenhouse gas (GHG) emissions increased by 21 %, 30 % and 36 % for the individualist, hierarchist and egalitarian perspectives.