The first generation of wind turbine (WT) blades are now reaching their end of life, signalling the beginning of a large problem for the future. Currently most waste is sent to landfill, which is not an environmentally desirable solution. Awareness of this issue is rising, but no studies have fully assessed the eco impact of WT blades. The present study aims to provide a macroscopic quantitative assessment of the lifetime environmental impact of WT blades. The first stage has been to analyse global data to calculate the amount of WT blade materials consumed in the past. The life cycle environmental impact of a single WT blade has then been estimated using eco data for raw materials, manufacturing processes, transportation, and operation and maintenance processes. For a typical 45.2 meter 1.5 MW blade this is 795 GJ (CO2 footprint 42.1 tonnes), dominated by manufacturing processes and raw materials (96% of the total. Based on the 2014 installed capacity, the total mass of WTB is 78 kt, their energy consumption is 82 TJ and the carbon dioxide footprint is 4.35 Mt. These figures will provide a basis for suggesting possible solutions to reduce WTB environmental impact.