The provision of electric lighting is not without consequences for the environment Electricity generation always causes pollution of the environment, either directly, as in air pollution caused by the burning of fossil fuels, or indirectly, when generating and transmission equipment has to be scrapped. But light itself can also be considered a form of pollution. Indeed, over the last two decades, public concern over the consequences of the use of light outdoors at night has been growing, driven by wellorchestrated advocacy campaigns using such emotive slogans as ‘Our children will never see the stars’.