In 2006, California was the first jurisdiction to mandate a reduction in greenhouse gas (GHG) emissions by 80% below 1990 levels by 2050. This target was subsequently endorsed by the G8 in 2009 and the European Commission in 2014, and is the principle guiding developed countries under the 2015 Paris agreement. To achieve these targets will require near elimination of fossil fuels from the energy mix and/or a technological breakthrough that is currently not on the horizon – a black swan event in other words. Eschewing nuclear power, countries are relying on wind, solar, biomass and some other renewable sources to meet future energy needs. In the seminar, I examine the prospects of reducing GHG emissions by 80% in the electricity sector. I will examine how investment choices are made, relying on two approaches that I refer to as the “load duration – screening” approach and the “merit order – math programming” approach. I will use data for Alberta (fossil fuel system) and British Columbia (hydro system with potential storage of intermittent energy). The driving factor will be recent legislation that will eliminate coal-fired power in Alberta, with greater reliance on wind and solar. I consider the role of conservation (smart grids) and the potential contribution of renewables to achieving the 80% target. I conclude that these ambitious targets cannot be attained without nuclear power.