Earth Hour began in Sydney in 2007 when 2.2 million homes and businesses turned off their lights for an hour. Two years later the symbolic gesture drew the attention of world leaders as over 60 countries participated in the event. Hundreds of millions of people worldwide turned off lights for a full hour.

This was a 25 hour energy-saving campaign spreading the visual message around the world. Environmentalists say nations now have a mandate to tackle climate change.

The pictures are spectacular. Log on to any major online newspaper and take a look at the sights ranging from The Empire State Building in NYC; in San Francisco The Golden Gate Bridge and other major city landmarks were dark for an hour; the Parthenon Temple on Acropolis Hill in Greece; The Houses of Parliament and Nelson’s Column in Trafalgar Square in London; the Eiffel Tower where 20,000 bulbs illuminating the town went out; in Rome even St. Peter’s Basilica at the Vatican (along with the Coliseum) were turned off; the Giza Pyramids in Egypt; the Bird Nest stadium was darkened for an hour; the iconic Christ the Redeemer statue that watches over Rio de Janeiro, along with the beachfront of the Copacabana. And, of course, The Sydney Opera House and Harbour Bridge were darkened – the city where this all began.

Many people participated in their own special way - in Indonesia a candle message was constructed saying VOTE EARTH in the Jakarta business district. In Manila people held up their mobile phones and glow sticks in front of a huge globe that is normally illuminated. Others decided to “freeze their movement” for a few minutes in Beijing, China.

“Earth Hour has always been a positive campaign,” said Earth Hour executive director Andy Ridley. “It’s always around street parties, not street protests, it’s the idea of hope, not despair. And I think that’s something that’s been incredibly important this year”

What a spectacular sight. And one of hope, not despair.