TORONTO -- The Canadian organizers of Earth Hour are hoping to breathe new life into the venture by looking to the stars.

The World Wildlife Fund, the driving force behind the symbolic stand against climate change, has enlisted a slew of homegrown celebrities to help draw attention back to a cause that has been losing ground in the public eye.

Since 2008, WWF has been urging people around the world to turn out their lights and power down their electronics for an hour as a gesture against global warming.

The Canadian chapter of the organization has launched a new campaign this year to try to encourage people to come up with solutions to the challenges posed by climate change.

In a series of 30-second videos, Canadian celebrities including Star Trek's William Shatner, actor and director Jason Priestly and astronaut Chris Hadfield offer quick reflections on how the world could look if people don't actively get involved in preserving the environment. The WWF is hoping the videos will encourage the public to share their own thoughts, either by recording their own video musings or taking the discussion to social media under the hashtag #momentofdarkness.

The new campaign comes at a time when Canadians' interest in Earth Hour appears to be waning.

Ipsos Reid polls conducted on behalf of the WWF suggest the number of Canadians powering down for the occasion has been steadily declining for the past few years.

Poll results suggested 16 million willingly went off the power grid in 2011, while 13 million became involved in 2012. Polling figures dropped again to 12.2 million participants for 2013.

WWF Canada President and former Toronto mayor David Miller said he hopes the new campaign will put a more concrete spin on Earth Hour while injecting a needed dose of optimism.

"Let's think about solutions because there are solutions," he said in a telephone interview. "I think that issue is one that can inspire people. We don't always just want to talk about problems. It's nice to know there's some hope for real positive change."

Concrete actions are the name of the game for Adam Korson, star of the Canadian television series "Seed" about a prolific sperm donor and his various offspring.

The Toronto native, whose interest in environmental issues has its roots in his love of hiking and surfing, recently bought a Prius hybrid gas-electric car in an effort to lead a more eco-friendly life.

Korson's video for the Moment of Darkness campaign sees him sounding off about the importance of containing wildfires, which he said can stand as a metaphor for global warming.

Much as the anti-littering campaigns of the 1980s forced people to weigh the consequences of their casual actions, Korson said he hopes the WWF's addition to the Earth Hour initiative will make people think about how the future could look if climate change isn't brought under control.

"I would love for my kids to walk out of the house and breathe clean air. I can only imagine my kids walking out and needing to put on a gas mask or an oxygen mask in order to get to school," Korson said. "While that sounds dramatic, that's not far off. I think it's a very short climb to that."

Some experts have grown wary of celebrity-based campaigns, openly questioning how effective they could be in an age of social media saturation.

Michael Abbass, vice-president of Paradigm Public Relations, said too many campaigns lack a clear connection between the famous spokesperson and the cause they're championing, citing the failed collaboration between BlackBerry and Alicia Keys as a prime example.

While none of the big names in the Moment of Darkness campaign have obvious green credentials, Abbass said the effort could still work because of the universal appeal of environmental causes.

"Logically the reason for their participation is because they are concerned about the planet and would like Canadians to help out and join the cause. You do not need to be a hard core environmentalist to authentically care about the planet and support this campaign," Abbass wrote in an email after reviewing the videos.

Earth Hour is embraced by hundreds of Canadian municipalities and many utilities have Earth Hour sections posted on their websites.

People wanting to participate are asked to power down at 8:30 P.M. local time on Saturday.