Earth Hour is an international event which takes place at the end of March each year. Participants in Earth Hour are encouraged to turn all of their nonessential lights off for one hour, starting at 8:00 PM. The event is designed to draw attention to the issue of wasted electricity, and to point out that small actions can make a significant difference in electricity consumption. Earth Hour also coincides with National Dark Sky Week in the United States, a week when people take action against light pollution by turning off extraneous lights.
The first Earth Hour took place in Sydney, Australia, in 2007. The event was sponsored by the Australian wing of the World Wildlife Fund (WWF) and the Sydney Morning Herald. During the event, the demand on Australia's electricity grid declined by around 10%, representing a substantial decrease in emissions created during electricity generation. In 2008, the event was repeated with cities all over the world, encouraging international participation.
Critics of Earth Hour argue that the reduction achieved during the hour of darkness is insignificant. However, Earth Hour is a symbolic event. Participants point out that if people made small conscious choices to reduce electricity consumption, these choices add up, and the hope is that Earth Hour participants will continue to reduce energy usage throughout the year, not just during Earth Hour.
The event also promotes the use of energy efficient lighting and policies in businesses which encourage energy efficiency. The goal of Earth Hour is to connect people with the issue of global warming on an immediate level, showing them how they can make a difference. Participating in Earth Hour is very easy, making the event simple to organize for communities which want to support it.
The organizers of Earth Hour would like to remind participants that only nonessential lights and appliances should be turned off during Earth Hour, and that people who feel the need to use candles should use products such as soy candles, which do not produce harmful emissions. Lights and appliances which need to be left on for safety reasons such as night lights in parking lots should not be turned off, although people are encouraged to use energy efficient bulbs and appliances. In addition to helping to preserve the environment, energy efficient lights and appliances also save money.