Never one to miss a party, Toronto has embraced Earth Hour with zeal. Enthusiasm is being whipped up with specialty cocktails, candlelit soirees, glow-in-the-dark soccer and a star-studded acoustic concert in Nathan Phillips Square featuring Nelly Furtado.
But when environmentalism is packaged as a party, the complexities of climate change could remain the great neon elephant in the room.
"Will this be the transformational moment we need? No, of course not," said Franz Hartmann, executive director of the Toronto Environment Alliance. "It will be another layer, another brick in the road to sustainability." Earth Hour alone won't change the world, but switching off for an hour can't hurt, he said, and it might just nudge some people along the conservationist's path.
"There is an environmental impact for every action. The whole point of this exercise is to be aware of that."
Toronto's fervour is unsurprising. City council is environmentally attuned, Mr. Hartmann said, and residents love the Web. (Facebook, anyone?) Plus, Earth Hour rekindles fond memories of the 2003 blackout.
But a quick glance at the Earth Hour website reveals mixed feelings about the event. Canada, the United States and Australia account for almost three-quarters of all registered participants. India has fewer than 5,000 people registered, China fewer than 1,700, and Antarctica has more participants than Monaco.
Impishly, "Burn fossil fuels for fun" ranks fourth on the list of national registrations.
Meanwhile, a quarter of humanity - 1.6 billion people - lives without any electricity at all.
Sarah van Schagen, assistant editor of environmental journalism and analysis website Grist.org, said Earth Hour's gimmicky veneer masks a real danger because people might feel they can get away with a high-energy lifestyle by doing just this one thing. "That's definitely not true," she said from Seattle, which has not signed on for Earth Hour. That's why education is a key part of the Earth Hour effort. "The reason people are jumping on board is because they … want to deal with climate change, but they might not know how."
Earth Hour's scope will be limited at some city landmarks. The Air Canada Centre will dim its outside lights, but the game will still get full wattage. The CN Tower will run fewer lifts to its dim-lit viewing platform. Pearson International Airport will reduce lighting in two terminals.
But elsewhere, people felt that the one-hour challenge was not enough. Woodbine Racetrack will use this Saturday night as a test run for reducing its lighting and heating systems year-round as part of its ongoing carbon-footprint reduction program.
Ecoholic author Adria Vasil spent a whole week living without power at her Riverdale home, discovering in the process that even she can find new ways to live more sustainably.
Ms. Vasil also fears that Earth Hour could produce unwanted results. "I want Torontonians to remember that we can't just conserve power for 60 minutes. We should be conserving it 365 days a year."
For Oakville Place marketing manager Kim LaRonde, two competitions brought home the difficulties of Earth Hour. The first asked shoppers to submit their conservation tips. Since the first prize was a trip to Australia, Oakville Place had to find ways to offset the flight emissions. Then it challenged the Australian shopping centre Sunshine Plaza to see which one could enlist the most Earth Hour participants.
Workers at the losing mall will wear hats sent by their opponent. Those hats had to be sent halfway round the world, though, and while the competition was conducted online to save paper, the Web is an energy drain.
"A lot of things are done with the best of intentions, [but]one small thing could detract from all those intentions," Ms. LaRonde said.
The key to success tonight, though, may lie in peer pressure, said Tom Heintzmann, president of Toronto-based renewable electricity provider Bullfrog Power. The energy impact will be "a drop in the bucket," but the message - especially for the only lit house on a residential street - may be powerful.
"When people take individual action in their own home, it feels inconsequential. Earth Hour is a short, quite tangible example of common action. That's a mind shift," he said.