On Saturday, March 29th, millions of people in more than 7,000 cities and over 150 countries will do something radical - Switch off all lights and electronic devices from 8.30-9.30pm local time! Why? Because believe it or not, this minor action that has become known throughout the world as 'Earth Hour' will help make a dent in the fight against climate change.

Earth Hour was first observed in 2007 in Sydney, when at the suggestion of the Australian Chapter of the World Wildlife Fund, 2.2 million households and 2,100 businesses, went dark for an hour. This small sacrifice helped save 10% of the electricity consumed by the city in a normal hour or the equivalent of carbon dioxide emitted by 48,000 cars in 60 minutes.

The impressive statistics of this simple act made such an impact worldwide, that in 2008, over 50 million people in more than 5,000 cities joined in. The numbers have only been growing since. Today, Earth Hour is the largest voluntary environmental event in the world. And it's not just households that go dark - Even iconic buildings like New York's Empire State Building and famous landmarks like San Francisco's Golden Gate bridge and Sydney's Opera House, join in.

Of course, one hour can only make a small difference in reversing global warming. That is why this year, the organizers are urging people to go 'beyond the hour' by reducing the waste they generate. A cognizant effort to recycle, reuse and reduce by every individual could make a huge difference.

This plea has inspired people all over the world to go beyond just switching off their lights and plan special events. In the Iranian city of Isfahan, Earth Hour celebration will be held near the Khaju Bridge to highlight the plight of the Zayanderud River. Once a robust flowing river, it has not had continuous water flow for the last few years. Locals attribute this to climate change and inadequate waste management. To demonstrate how dire the situation is, residents of the area have created a 2,800 square meter logo (the largest yet), of the Earth Hour symbol, on the dry river bed

In Tahiti, French Polynesia, the event is being celebrated with an acoustic concert with a twist. Instead of buying tickets, the audience have been asked to bring recyclable waste. Before being allowed into the arena, they will be directed to the red carpet where they will photographed sorting out the recyclables they have brought.

In Belgium, people that sign up to celebrate Earth Hour are in for a treat - A live performance from a musical band in the comfort of their homes. Entitled 40 bands - 40 Living Rooms in Belgium, it was organized to encourage more people to join in the effort for at least this one hour and maybe, for the rest of their lives.

Even the cast of The Amazing Spider-Man 2 is getting into the sprit. Andrew Garfield, Emma Stone, Jamie Foxx and director Marc Webb, will be present when Singapore's famous Marina Bay goes dark for an hour on Saturday. Their message? Anyone can be a Superhero for the planet!

Are you ready to take the challenge? Can you set aside just one hour on Saturday to make a difference? if so, be sure to sign your pledge at earthhour.org. And, don't forget to spread the word so that everyone can do his or her share in saving our planet - One light bulb at a time!

Resources: Earthhour.org.