Consider Earth Hour 2008 as a global S.O.S. signal.

At 8 p.m. on Saturday, March 29, millions of people around the world will be turning off their lights for one hour - part of an international effort to raise awareness about climate change and send a message to governments about the need for action.

The initiative is the brainchild of the World Wildlife Fund, which organized last year's inaugural Earth Hour as an isolated event in Sydney, Australia. At the time, Australia had not yet signed the Kyoto Protocol.

The original goal was to involve 100,000 individuals and businesses, but when 2.2 million people ended up participating - and reduced Sydney's total energy output by 10.2% for the hour by doing so - WWF staff realized they had a winning idea on their hands and decided to take the initiative to the global stage.

Over 20 countries are involved in this year's Earth Hour, and Canada is leading the pack in terms of participation, with over 30,000 individuals and almost 100 cities already registered to take part.

The widespread support doesn't surprise Julia Langer, director of climate change programs at WWF-Canada, who says Canadians care deeply about global warming and its effects, even if our federal government has yet to address the issue in a meaningful way.

"We have a very problematic dichotomy between public will and political will," Langer says. "This has been about how the average person and businesses can actually indicate their concerns and expectations for action."

WWF-Canada has focused its 2008 planning efforts on Toronto, with Nelly Furtado set to perform a free, unplugged street concert and Air Canada Centre committed to turning off its exterior lights during the evening's NHL game.

Here in Winnipeg, the lights at City Hall and Manitoba Hydro office buildings will be shut off for the hour. From 8 to 10 p.m., the Royal Astronomical Society will be hosting a public star-gazing event at the duck pond in Assiniboine Park, while St. Andrew's River Heights United Church (located at 255 Kingsway) will be putting on a Earth Hour service from 7:45 to 8:30 p.m. that will feature readings, music, and a speech by Dr. Jon Gerrard, leader of the Manitoba Liberal Party.

Ultimately, Langer says the hope is for people to use Earth Hour as a starting point for further action. To that end, WWF-Canada is using the initiative as a launch pad for its newest campaign, the Good Life, which allows people to create individual savings accounts that measure the effects of their actions on greenhouse gas reductions. These accounts will then be combined with ongoing provincial and federal tallies to show citizens that every action, no matter how small, really does makes a difference.

But even as a symbolic gesture, Langer says Earth Hour has value because it can kick-start widespread public engagement. She notes, for example, that shortly after last year's event in Sydney, the reigning government was defeated by a party that had promised to ratify Kyoto - which Kevin Rudd did as his first official action as Australia's new Prime Minister.

"Turning out the lights is something everyone can do," Langer says. "Obviously, this is not going to save the world - but this is our signal that we need to save the world."

For more information on Earth Hour or to register, go to www.earthhour.org.