China joins Earth Hour

This year will be the first time China has joined in on Earth Hour. For environmentalists, it will be one of the most powerful images to see many of China's architectural landmarks suddenly going dark.

The whole point of Earth Hour is to promote environmental awareness and reaching China's 1.3 billion people is certainly a boost to the global environmental movement.

Securing the participation of China's cities in a country that is home to a fifth of the globe's population – and the biggest emitter of carbon dioxide in the world – is a good start.

Organizers of Earth Hour believe China's participation will send a powerful message around the world.

"That two of China's most iconic landmarks – the Shanghai skyline and the Olympic Green – will be part of this year's effort will send a message to the rest of the world that the people of China are committed to taking action on climate change," says Dermot O'Gorman, country director of the World Wildlife Federation, the organization that inspired the movement.

"Ordinary people, too, in many cities have now signed up to switch off," he says.

Beijing and Shanghai aren't just any two cities. Their combined populations total more than 36 million – more than the entire population of Canada. They represent a huge boost to Earth Hour's global effort.

During a briefing in Beijing last week, Angel Gurria, the head of the Organization for Economic Co-operation and Development, said: "No global issue can be addressed properly without China in its midst."

Other major Chinese cities also participating include Hong Kong, Macau, Baoding, Dalian, Nanjing – where a valley of 80 skyscrapers will switch off – and countless smaller cities and towns.

They'll join hundreds of millions others – organizers hope the global total will exceed 1 billion – throughout 84 countries - for the first time.

In Beijing – in restaurants, on campuses and in private homes – there's a nascent enthusiasm about joining a global movement. The city's popular Bookworm, a bookshop and eatery, sent out an email to customers this week inviting them all for a candlelit dinner.