A measure of life-cycle greenhouse gas emissions is an attempt to calculate the global-warming potential of electrical energy sources by doing a life-cycle assessment of each energy source and presenting the findings in units of global warming potential per unit of electrical energy generated by that source. The scale uses the global warming potential unit, the Carbon dioxide equivalent (e), and the unit of electrical energy, the kilowatt hour (kWh). These assessments attempt to cover the full life of the source, from material & fuel mining, through construction, to operation and waste management.