Copper mining waste reprocessing company Big Tree Copper CE Jan Nelson expects a steady climb in demand for copper over the next three decades, as the world has turned its full attention to sustainable energy and a greener economy. Demand is expected to exceed supply, with an expected to upward trajectory of about 16% to 20% by the end of the decade. At current production rates, a deficit of at least six-million tonnes is forecast. It is a key component in green energy, from electric cars to wind turbine power supply.