Electricity for lighting accounts for between 15 % (UNEP, 2014) and 19 % (IEA, 2006) of global electricity consumption and between 5 and 6 % of worldwide CO2 emissions. A global transition to widely available efficient solutions in all lighting sectors (residential, commercial/industrial and outdoor) by 2030 could reduce electricity demand for lighting by more than 32 %, and avoid 3.5 Gt of CO2, while significantly cutting electricity bills, reducing fuel imports and black outs, and improving end-user welfare. The transition would save over $ 120 billion annually in avoided electricity bills to consumers, through a reduction of over 1,000TWh of electricity every year. It would also save over to $230 to 425 billion in avoided investment in 280 large (500 MW) base-load to 520 large peak-load power plants. Furthermore, if the world leapfrogged to LED lamps in all sectors, it would reduce global electricity consumption for lighting by more than 52 % and avoid 735 million tonnes of avoided CO2 emissions each year.