If we are to achieve the Paris climate commitments to limit warming to well below 2 degrees Celsius and, if possible, 1.5 degrees Celsius, «revolutionary changes»1 to the global energy system are going to be necessary, as stated by the IEA. According to a joint 2017 study by the IEA and IRENA, the Paris targets «require an energy transition of exceptional scope, depth and speed. Energy-related CO2 emissions would need to peak before 2020 and fall by more than 70 % from today's levels by 2050.