Don’t be alarmed if your city, town, or neighborhood, goes dark from 8:30 - 9:30 PM local time tonight (March 24). The blackout is not due to a sudden electricity outage, but a voluntary gesture to celebrate Earth Hour, which will be observed worldwide and include iconic landmarks like the Eiffel Tower, the Empire State Building, and the Sydney Opera House. The simple action, designed to demonstrate what can be achieved if we all unite to help reverse climate change, is the brainchild of the Australian chapter of the World Wildlife Fund (WWF).

Earth Hour was first observed in Sydney on March 31, 2007, when, at the urging of the nonprofit, 2 million households and 2,100 businesses turned off all lights and non-essential devices for an hour. In doing so, they helped save 10% of the electricity, the equivalent of carbon dioxide emitted by 48,000 cars, consumed by the city's residents in a regular evening hour. The environmental impact of the one-hour event inspired people worldwide to join the movement. In 2008, 50 million people in over 5,000 cities observed Earth Hour and the numbers have only grown since. In 2017, tens of millions of people from an unprecedented 187 countries and territories participated and over 3,100 monuments and landmarks switched off their lights.

The date of the annual event varies from mid-to-late March to coincide, as much as possible, with the spring and autumn equinoxes in the northern and southern hemispheres, respectively, when both experience sunset at about the same time. This ensures the best visual impact and makes for impressive images of the usually glimmering city skylines going dark.

The WWF says the worldwide participation demonstrates people's desire to do their share to reverse climate change. For those that want to make a difference beyond the hour, the organization suggests simple lifestyle changes. These include air-drying dishes, unplugging all devices when not in use, walking or bicycling to work, and washing clothes in cold water.

Not sure what to do without your phone, tablet, and television for a whole hour? WWF suggests organizing a candlelight dinner for your family or, even better, a picnic under the stars. If that sounds “lame” how about a late night hike or bike ride? Those that want to make it an Earth “Night” could plan a camping trip complete with an old-fashioned bonfire and yummy s'mores! Ready to take the Earth Hour challenge? Sign up at earthhour.org and commit to “switching on your social power” to help spread the word. Climate change can be reversed if we all do our part!

Happy Earth Hour!

Resources: Earthhour.org.wikipedia.org