The main economic goal of copper consumer is to maximize certain benefits, while the goal of copper manufacturers is maximizing the profit. From an economic point of view, the optimum level between these two goals, is the one where the difference between the cost and economic impact is greatest. However, the economic optimum level may not be the best from the environmental point of view. The focus of the paper is on the production and consumption of copper in the world, as well as the performance of the price of copper on LME (London Metal Exchange). Bearing in mind that the production of copper resulting external costs that are not included in the price of copper, the aim of the paper refers to point out the significance of introducing external cost in the model of supply and demand of copper in the stock market.