Earth Hour is a worldwide movement organized by the World Wildlife Fund (WWF). The event is held annually, encouraging the individuals, communities, and businesses to give an hour for Earth, and additionally marked by landmarks and businesses switching off non-essential electric lights, for one hour from 8:30 to 9:30p.m., usually on the last Saturday of March, as a symbol of commitment to the planet. It was started as a lights-off event in Sydney, New South Wales, Australia, in 2007.

Occasionally, in years when Holy Saturday falls on the last Saturday of March (as in 2024), Earth Hour is held a week earlier.

History of Earth Hour

Conception and start: 2004–2007 In 2004, confronted with scientific findings, WWF Australia met with advertising agency Leo Burnett Sydney to "discuss ideas for engaging Australians on the issue of climate change". The idea of a large scale switch off was coined and developed in 2006, originally under the working title "The Big Flick". WWF Australia presented their concept to Fairfax Media who, along with Sydney Lord Mayor Clover Moore, agreed to back the event. The 2007 Earth Hour was held on March 31 in Sydney, Australia at 7:30pm, local time.

In October 2007, San Francisco ran its own "Lights Out" program inspired by the Sydney Earth Hour. After their successful event in October, the organizers decided to rally behind the Earth Hour being planned for March 2008.

2008

Earth Hour 2008 was held internationally on March 29, 2008, from 8p.m. to 9p.m. local time, marking the first anniversary of the event. Thirty five countries around the world participated as official flagship cities and over 400 cities also supported. Landmarks around the world turned off their non-essential lighting for Earth Hour. Some websites took part in the event, with Google's homepage going "dark" on the day.

According to a Zogby International online survey, 36 million Americans—approximately 16% of the United States adult population—participated in Earth Hour 2008. The survey also showed there was a 4-percentage point increase in the level of interest in environmental issues such as climate change and pollution directly after the event (73 percent pre-event versus 77 percent post-event).

Tel Aviv scheduled their Earth Hour for Thursday March 27, 2008 to avoid conflict with Sabbath. Dublin moved their Earth Hour to between 9 and 10p.m. due to their northern geographical location.

According to WWF Thailand, Bangkok decreased electricity usage by 73.34 megawatts, which, over one hour, is equivalent to 41.6 tonnes of carbon dioxide. The Bangkok Post gave different figures of 165 megawatt-hours and 102 tonnes of carbon dioxide. This was noted to be significantly less than a similar campaign initiated by Bangkok's City Hall the previous year in May, when 530 megawatt-hours were saved and 143 tonnes of carbon dioxide emission were cut.

Philippine Electricity Market Corp. noted that power consumption dropped by about 78.63 megawatts in Metro Manila, and up to 102.2 megawatts on Luzon. The maximum demand drop of around 39 MW was experienced at 8:14p.m. in Metro Manila and of around 116 MW at 8:34p.m. in the Luzon grid.

Ontario used approximately 900 megawatt-hours less electrical energy during Earth Hour. At one point, Toronto saw an 8.7% reduction in consumption as compared to a typical March Saturday night.

Ireland, as a whole, had a reduction in electricity use of about 1.5% for the evening. In the three-hour period between 6:30p.m. and 9:30pm, there was a reduction of 50 megawatts, saving 150 megawatt-hours, or approximately 60 tonnes of carbon dioxide.

In Dubai, where external lighting on several major city landmarks was turned off and street lighting in selected areas was dimmed by 50%, the Electricity and Water Authority reported savings of 100 megawatt-hours of electricity. This represented a 2.4% reduction in demand compared to before the hour began.

The best result was from Christchurch, New Zealand, with the city reporting a drop of 13% in electricity demand. However, national grid operator Transpower reported that New Zealand's power consumption during Earth Hour was 335 megawatts, higher than the 328 megawatt average of the previous two Saturdays.Lights on, power use up for Earth Hour . Kelly Andrew. The Dominion Post. Monday, March 31, 2008. Melbourne, Australia reduced demand by 10.1%. Sydney, being the city that participated in both the 2007 and 2008 Earth Hours, cut electricity consumption by 8.4%. This is less than the previous year's 10.2%; however, Earth Hour executive director Andy Ridley made the claim that after factoring margin of error, the participation in this city was the same.

The worst result was from Calgary, Canada. The city's power consumption actually went up 3.6% at the hour's peak electricity demand. Calgary's weather plays a large role in power consumption, and the city experienced weather 12°C (around 22°F) colder than the previous Saturday's recorded temperature in the inaugural year. Enmax, the city's power supplier, has confirmed that in all subsequent years, Calgarians have not supported the Earth Hour initiative, noting that power consumption changed only marginally during the hour in 2010 and 2011 (1% or less) and in 2012 and 2013 showed no appreciable change in power usage at all.

2009

Earth Hour 2009 was from 8:30p.m. to 9:30p.m. local time, March 28, 2009. The campaign was titled "Vote Earth" and was dubbed "the world's first global vote" with one billion votes was the stated aim for Earth Hour 2009, in the context of the pivotal 2009 United Nations Climate Change Conference. WWF reported that 88 countries and 4,159 cities participated in Earth Hour 2009, ten times more cities than Earth Hour 2008 had (2008 saw 400 cities participate).

Among the participants in 2009 was, for the first time, the United Nations Headquarters in New York City.

In Egypt, the lights went out on the Sphinx and the Great Pyramids of Giza from 8:30 to 9:30 pm.

The Philippines saw participation from 647 cities and towns; over 10 million Filipinos were estimated to have joined in the hour-long lights-off. This was followed by Greece with 484 cities and towns participating, and Australia with 309.

Despite official organizers WWF stating that the event is not about the reduction in electricity, a number of public institutions reported on electricity savings in their cities to see participation numbers. The Canadian province of Ontario, excluding the city of Toronto, saw a decrease of 6% in electricity usage while Toronto saw a decrease of 15.1% (nearly doubled from 8.7% the previous year) as many businesses darkened, including the landmark CN Tower.

The Philippines was able to save 611 MWh of electricity during the time period, which is said to be equivalent to shutting down a dozen coal-fired power plants for an hour.

Swedish electricity operator Svenska Kraftnät recorded a 2.1% decrease in power consumption from its projected figure between 8p.m. and 9pm. The following hour, the corresponding number was 5%. This is equivalent to the consumption of approximately half a million households out of the total 4.5 million households in Sweden.

According to the National Power Dispatch Centre, Vietnam's electricity demand fell 140 MWh during Earth Hour.

2010

Earth Hour 2010 was held from 8:30p.m. to 9:30p.m. local time on March 27. In Israel, the hour was held on April 22. 126 countries participated in Earth Hour 2010.

In the United States polling showed that an estimated 90,000,000 Americans participated in Earth Hour as lights were turned off around the country, including landmarks such as Mount Rushmore, the Las Vegas Strip, the Empire State Building and Niagara Falls.

Some cities and landmarks took the opportunity to make more long-term adjustments to their everyday power consumption. In Chicago, the Building Owners and Managers Association (BOMA) developed lighting guidelines to reduce light pollution and reduce the carbon footprint of downtown buildings. Mount Rushmore in South Dakota started powering down each night around 9 p.m. instead of 11 p.m.

In Vietnam, electricity demand fell 500,000 kWh during Earth Hour 2010, which was three times larger than the first time the country joined the event in 2009.

In the Philippines, 1,067 towns and cities pledged participation in 2010 and over 15 million Filipinos participated in the event.

About 4,000 cities participated, including landmarks such as Big Ben, the Empire State Building, the Sydney Opera House, the Eiffel Tower, the Parthenon, the Brandenburg Gate, and the Forbidden City.Alastair Jamieson (March 27, 2010). Big Ben in darkness as 4,000 cities switch off for Earth Hour. The Telegraph. Retrieved April 6, 2009.

2011 Earth Hour 2011 was the biggest year in the campaign's five-year history, reaffirming it as the largest ever voluntary action for the environment. In 2011, the tagline "Beyond the Hour" was adopted by organizers as a way to encourage people to take their commitment to the cause beyond the 60-minute event. Together with agency Leo Burnett, Earth Hour unveiled an updated planet themed logo that included a small plus symbol to the right of the signature "60" which was used in previous years. The 60+ symbol continues to be the main logo used by campaign organizers around the world.

Earth Hour 2011 took place in a record 5,251 cities and towns in 135 countries and territories on all seven continents. It had an estimated reach of 1.8 billion people across the globe. In addition to this, the campaign's digital footprint grew to 91 million.

In India, Earth Hour 2011 was held on March 26, 2011, from 8:30p.m. to 9:30pm. IST, flagged off by the Chief Minister of Delhi Sheila Dikshit and Earth Hour 2011 Ambassador and Bollywood actress Vidya Balan in the presence of Jim Leape, Director General, WWF International. Rosebowl channel suspended broadcasting from 8.30p.m. to 9.30p.m. to mark the observance of Earth Hour.

In Azerbaijan, Maiden Tower darkened for Earth Hour.

The Philippines, which has been an active participant of the Earth Hour, had an early "earth hour" when power was accidentally interrupted, plunging Metro Manila and nearby provinces into darkness. After power was restored, major buildings, commercial centers and residential areas in Metro Manila and most provinces continued to turn off their lights, while participating channels in the Philippines, ABS-CBN, Nickelodeon and Cartoon Network halted their transmissions for an hour.

Thirty provinces and cities in Vietnam took part in Earth Hour 2011 with the main event held in Nha Trang. The nation's electricity demand fell 400,000 kWh, one-fifth less than the previous year's. Vietnam managed to save 500 million VND (US$23,809) thanks to the saved power.

YouTube promoted the Earth Hour by changing its logo, and by adding a switch on/off feature near the title of each video, so that users could change the background colour from white to black.

One of the least co-operative areas traditionally has been Alberta; in 2008, Calgary's power consumption went up during Earth Hour. The trend continued in 2011 when Edmonton's power usage also increased. While Calgary's power usage went down in 2011 during the event, electricity officials could not distinguish their readings between normal usage and a conscious attempt to participate.

2012 Earth Hour Global headquarters was moving from Sydney to Singapore in February 2012. A launch event took place at ION Orchard on February 20, with the move supported by Singapore's Economic Development Board (EDB) and WWF-Singapore.