A combination picture shows Sydney's famous Opera House and Harbour Bridge before (top) and after the lights were turned off for Earth Hour March 28, 2009. Lights went out at Sydney's Opera House and Harbour Bridge on Saturday for Earth Hour 2009, a global event in which landmarks and homes go dark for an hour to highlight the threat from climate change.[Xinhua/AFP]

He also stressed that the essence and importance of the save- planet campaign is to let ordinary people join the movement. " Earth Hour is owned by the people and anyone who wants to be part of Earth Hour can be."

Ridley said apart from turning off the lights on Saturday night, people can also celebrate Earth Hour in their own special way, whether it is a candle-light dinner with family members or Earth Hour event organized by local community.

"We ask that you turn off your lights for one hour and any other non-essential appliances to get you to consider other simple acts you could incorporate into your everyday life to conserve energy. Through the symbolic act of switching your lights off we hope that people take the Earth Hour message and absorb it into their life beyond one hour, so every hour is Earth Hour."

He conceded that turning off the lights for one hour in a year can not do much to improve the climate, but Earth Hour can at least provide a platform for public desire for a better, healthier world.

"Earth Hour is a symbolic act. It's a time to reflect on what you can do as an individual, business or community to be more sustainable. It has evolved from the simple act of turning off your lights for one hour to a global show of solidarity among concerned citizens of the world who want the issue of climate change resolved."