Explaining Earth Hour

A hand moving to turn off a light switch

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Earth Hour is an annual event, usually held on the last Saturday evening in March when millions of people and thousands of businesses worldwide turn off lights and shut down most electrical appliances to celebrate sustainability and show their support for strategies that will help solve the problem of global warming.

The First Earth Hour

Earth Hour was inspired by a demonstration in Sydney, Australia on March 31, 2007, when more than 2.2 million Sydney residents and more than 2,100 businesses switched off lights and non-essential electrical appliances for one hour to make a powerful statement about the leading contributor to global warming: coal-fired electricity.

That single hour accounted for a 10.2 percent reduction in energy consumption across the city. Global icons such as the Sydney Opera House went dark, weddings were held by candlelight, and the world took notice.

Earth Hour Goes Global

What began in 2007 as one city’s dramatic stand against global warming has become a global movement. Sponsored by WWF—a conservation group that aims to reduce greenhouse gas emissions from electricity generation by 5 percent annually—Earth Hour has the official participation of a growing number of cities, countries, businesses, and individuals worldwide.

Just one year later, in 2008, Earth Hour had become a global movement, with more than 50 million people in 35 countries and territories taking part. Global landmarks such as the Sydney Harbour Bridge, the CN Tower in Toronto, San Francisco's Golden Gate Bridge, and the Colosseum in Rome stood as silent darkened symbols of hope and sustainability.

In March 2009, hundreds of millions of people took part in the third Earth Hour. More than 4000 cities in 88 countries and territories pledged their support for the planet by switching off their lights.

Earth Hour grew again in 2010, as 128 countries and territories joined the global cause of climate action. Iconic buildings and landmarks on every continent but Antarctica—and people from nearly every nation and walk of life—switched off to show their support.

In 2011, Earth Hour added something new to the annual event, urging participants to "go beyond the hour" by committing to at least one environmental action they could continue all year long that would help make the world a better place.

The Purpose of Earth Hour

The goal, of course, is to inspire people to reduce their energy consumption every day not by sitting in the dark for an hour each night but by taking simple steps that can have a dramatic effect.

A Few Examples

  • Switch to energy-efficient CFL or LED lights instead of traditional incandescent bulbs (even Thomas Edison, who invented incandescent bulbs, was a proponent of renewable energy and reducing energy consumption). Lighting accounts for about 5 percent of residential greenhouse gas emissions.
  • Turn off or unplug computers, televisions, cell-phone chargers, microwave ovens, and other appliances and electrical devices when they’re not in use instead of leaving them on standby.
  • Turn off lights when you leave a room or finish work for the day. Encourage your company to shut off lights and unused appliances when no one is working.
  • Heat only the rooms you use regularly and adjust your thermostat to keep your home a little cooler in winter and a little warmer in summer.
  • Get a free home energy audit to help you reduce your energy consumption, and switch to green power if your utility company offers renewable energy options.
  • Use less hot water. This will not only save water, it will also reduce the amount of electricity (or natural gas) you use to keep water hot.

Wondering what you can do after the lights go out? WWF suggests several possibilities, such as dinner by candlelight (preferably with Earth-friendly beeswax candles), an Earth Hour block party, or a nighttime picnic with family or friends. And while you're doing that, give some thought to what else you can do to help protect and preserve the environment.

To learn more about Earth Hour and get involved, visit the Earth Hour website.