Australia's largest city was shrouded in darkness on Saturday night as it launched a worldwide campaign stretching from Sydney to San Francisco to highlight global warming.


Sydney was the first major metropolis to mark Saturday's 'Earth Hour', a self-imposed 60-minute black-out, with the lights on landmark buildings, corporate skyscrapers, businesses and homes switched off from 8:00 pm (0900 GMT).
From there the initiative, which aims to engage the community in combatting global warming, will see lights dimmed or turned off at 8:00 pm local time in Asian cities such as Bangkok and Manila, before spreading further to Europe and the Americas. Tel Aviv marked the event on March 27 for religious reasons.
'Earth Hour' founder Andy Ridley, who has said up to 30 million people could participate this year, said he was amazed at how far the initiative had spread since it was launched by environmental group WWF in Sydney a year ago.
"When we first talked about it, right at the beginning, our dream was to come up with something that made sense to a lot of people to do," he told AFP.
"And what seems to have happened is that it does seem to make sense to a lot of people to do it."
'Earth Hour' encourages governments, companies and homeowners to voluntarily switch off power to non-essential appliances for one hour to illustrate how, by working together, people can make a difference by using less energy, thereby producing fewer greenhouse gas emissions.
About 2.2 million people are estimated to have participated in the 2007 Sydney event which left the city's iconic harbourside Opera House and nearby Harbour Bridge bathed in moonlight as restaurant diners ate by candlelight and company logos on office buildings were dimmed.
'Earth Hour' Australia chief executive Greg Bourne said with 370 cities, towns and local governments across 35 countries taking part, he expected tens of millions of people to participate in 2008.
"I'm putting my neck on the line but my hope is that we top 100 million people," he said.
He said 'Earth Hour' carried "a message of hope and optimism... (that) we, the citizens of the world, are prepared to take action and we want to defeat climate change."
At 8:00 pm, Sydney's Harbour Bridge and Opera House dimmed as the floodlights were turned off, leaving only security lighting on. Elsewhere in the central business district, office lights were turned off.
Twenty-six cities around the world are officially signed on to turn off their lights on Saturday night, including Chicago and Atlanta in the US and the Irish capital Dublin, but hundreds more towns and local governments are expected to be involved in the 60-minute shutdown.
In Bangkok, the lights on some of the Thai capital's most famous landmarks, including the riverside Temple of the Dawn, the Rama 8 Cable Bridge across the Chao Phraya River and the main boulevard in the city's historic core will be turned off.
Sawaeng Tankam, 50, a motorcycle taxi driver, said authorities should expand the campaign to more areas.
"Why do they switch off the lights only in a few areas? That doesn't do enough to save energy. They should do this in every district in the city or even better, in every province," he said.
Some people in the Thai capital said they didn't know about the campaign.
"Switch off the lights? Where?" said Prapunpong Kaewyaem, 28, a vendor selling brass statues on Rajdamri Road, one of the thoroughfares set to turn off its street lamps.
Others voiced concern about the city plunging into darkness.
"I don't like it. This doesn't help anything. It is going to be dark," said Supoj Jaidee, a self-employed 30 year old.
Meanwhile in Manila, several major thoroughfares will go dark as street lights and billboards are switched off on the designated hour, Philippine Energy Secretary Angelo Reyes said.
Cities involved in 'Earth Hour' include Aalborg, Aarhus, Adelaide, Atlanta, Bangkok, Brisbane, Canberra, Chicago, Christchurch, Copenhagen, Darwin, Dublin, Hobart, Manila, Melbourne, Montreal, Odense, Ottawa, Perth, Phoenix, San Francisco, Suva, Sydney, Tel Aviv, Toronto and Vancouver.