Earth Hour is organized by WWF. With almost 5 million supporters and a global network in over 100 countries, it’s one of the world's largest and most respected independent conservation organizations. WWF’s mission is to stop the degradation of the Earth's natural environment and build a future where people live in harmony with nature.

Earth Hour started in 2007 in Sydney, Australia when 2.2 million individuals and more than 2,000 businesses turned their lights off for one hour to take a stand against climate change. Only a year later and Earth Hour had become a global sustainability movement with more than 50 million people across 35 countries participating. Global landmarks such as the Sydney Harbour Bridge, CN Tower in Toronto, Golden Gate Bridge in San Francisco, and Rome’s Colosseum, all stood in darkness, as symbols of hope for a cause that grows more urgent by the hour.

In March 2009, hundreds of millions of people took part in the third Earth Hour. Over 4000 cities in 88 countries officially switched off to pledge their support for the planet, making Earth Hour 2009 the world’s largest global climate change initiative.

On Saturday 27 March, Earth Hour 2010 became the biggest Earth Hour ever. A record 128 countries and territories joined the global display of climate action. Iconic buildings and landmarks from Asia Pacific to Europe and Africa to the Americas switched off. People across the world from all walks of life turned off their lights and came together in celebration and contemplation of the one thing we all have in common – our planet.

Earth Hour 2011 took place on Saturday 26 March at 8.30PM (local time). It?continued to be a call to action to every individual, every business and every community throughout the world. A call to stand up, to take responsibility, to get involved and lead the global journey to a sustainable future.

地球一小時是世界自然基金會應對全球氣候變化所提出的一項倡議，希望個人、社區、企業和政府在每年3月最后一個星期六20：30-21：30熄燈一小時，來表明他們對應對氣候變化行動的支持。過量二氧化碳排放導致的氣候變化目前已經極大地威脅到地球上人類的生存。公眾只有通過改變全球民眾對于二氧化碳排放的態度，才能減輕這一威脅對世界造成的影響。繼2009年之后，2010年3月27日，地球一小時活動再次在全球展開。

“地球一小時”活動首次于2007年3月31日晚間8：30在澳大利亞悉尼市展開，當晚，悉尼約有超過220萬戶的家庭和企業關閉燈源和電器一小時。事后統計，熄燈一小時節省下來的電足夠20萬臺電視機用1小時，5萬輛車跑1小時。更多參與的市民反映，當天晚上能看到的星星比平時多了幾倍。

隨后，“地球一小時”從這個規模有限的開端，以令人驚訝的速度很快席卷了全球。僅僅一年之后，“地球一小時”就已經被確認為全球最大的應對氣候變化行動之一，成為一項全球性并持續發展的活動。2008年3月29日，有35個國家多達5000萬民眾參與其中，并證明了個人的行動凝聚在一起真的可以改變世界。

相關閱讀

全球熄燈響應“地球一小時”

“地球一小時”活動視頻

世界各地熄燈響應“地球一小時”

'Big Tree' formed to mark Earth Day

（中國日報網英語點津 Julie 編輯）