This year, Earth Hour will be on March 24 from 8:30 to 9:30 p.m.
The event, organised by the World Wildlife Fund (WWF), began in Sydney in 2007 and has grown into the world's largest grassroots movement for the environment.
Earth Hour lasts for just 60 minutes and its power is purely symbolic.
The world will celebrate Earth Hour on Saturday night by switching off lights and going "dark" for one hour to encourage participation in fighting climate change. "Earth hour is an opportunity to show our resolve to change".
Said WWF Singapore's chief executive Elaine Tan: "We face an urgent global crisis on plastics - one that we as humans are responsible for. And this Earth Hour, these leaders are uniting with Americans from all walks of life to build a more renewable, prosperous future".
"Funds raised for Earth Hour are used to support Greenrock's community projects and programs which help to create a more sustainable Bermuda".
Emirates Global Aluminium said it had saved over 70,000 kilowatt hours of electricity in the past year through weekly observance of Earth Hour.
"The President has recognized this and has made the protection of the environment a priority during his State of the Nation Address", Presidential Spokesperson Harry Roque said in a statement hours ahead of Earth Hour. Carnaby Street's arch has been given a make over in support of Earth Hour and local businesses aim to take part.
Meant to engage Australians on the issue of climate change, the first Earth Hour was held on 31 March 2007 at 7:30pm local time. WWF is a dynamic partner of the Secretariat of the UN Convention on Biological Diversity, helping to raise awareness of the importance of biodiversity and nature for people and communities worldwide.. Rather, it's a chance to put the spotlight on the issues facing the planet, and to inspire millions across the world to live more sustainably.
In Christchurch, New Zealand, the city saw a 13 per cent drop in electricity demand during the hour.