It has been called "the world's largest awareness movement on climate change."
Critics aver, saying it could actually be sending the wrong message.
The World Wildlife Fund (WWF) launched the Earth Hour 2010 campaign in Vietnam last month.
The WWF wants every light in Vietnam and in the world to go dark for one hour on March 27 as a symbolic action to seek greater awareness of climate change. All Vietnamese citizens and businesses are being urged to participate by turning out lights and shutting off appliances for one hour from 8:30 p.m., the organizers said.
"This year we are aiming for at least 1,000 businesses to participate. We already have 18 provinces signed up," said Julianne Becker, WWF Vietnam Communication Manager.
Around the globe, among the places where the lights will go out are the world's most iconic landmarks such as Golden Gate Bridge in San Francisco, Grand Palace in Bangkok, Table Mountain in Cape Town, the London Eye, Hiroshima Peace Memorial, Empire State Building, and Burj Khalifa in Dubai.
"It's a demonstration of public concern about climate change it's the people of the world saying they care about the future of the planet," WWF's Julianne Becker told Thanh Nien Weekly.
But a prominent European critic said although it is perceived as an environmental event, Earth Hour is an entirely symbolic gesture.
"It gives the mistaken impression that the solution to climate change is as easy as turning off a light," said Dr. Bjorn Lomborg, author of "The Skeptical Environmentalist" and director of the Denmark-based think tank Copenhagen Consensus Center.
Asked how much energy would be saved during 60 minutes of darkness, Becker said WWF would not release energy saving estimates or calculate the emissions saved.
"That's not the point," she said.
"Earth Hour campaign is not about the energy saved during the hour."
Lomborg even pointed out that even if energy savings were achieved during the event, it would be just a drop in the ocean.
"Even if two billion people are able to save ten tons of carbon during that hour, that's the equivalent of just 0.0000125 percent of Vietnam's annual carbon emissions," Lomborg told Thanh Nien Weekly.
In an op-ed article in The Australian last year, Lomborg also said the event could actually increase emissions.
"When asked to extinguish electricity, people turn to candle light," he wrote.
"Candles seem natural, but are almost 100 times less efficient than incandescent light globes, and more than 300 times less efficient than fluorescent lights. If you use one candle for each extinguished globe, you are essentially not cutting CO2 at all, and with two candles you will emit more CO2."
"Moreover, candles produce indoor air pollution 10 to 100 times the level of pollution caused by all cars, industry and electricity pollution," he added.
Becker admitted it was hard to measure specific results for a campaign like Earth Hour because the results cannot be seen immediately. However, one tangible benefit is growing awareness of climate change, she stressed.
But Lomborg said he also doubted this.
"The tangible benefits are minimal. If anything, events like this make people believe that stopping global warming is easy, when in fact we really need people to realize that it will be hard and almost impossible without more innovation."
Lomborg and Becker were agreed, however, that there was a desperate need to focus on developing green energy to tackle climate change.
"A meaningful solution to global warming shouldn't focus on reducing carbon emissions but on developing green energy that is, energy technologies that do not produce greenhouse gases," Lomborg said.
"Instead of trying to make carbon-emitting fuels more expensive, we need to make green energy cheap."
"To do this we need strong leadership from our governments because it requires decisive economic action investment in renewable energy is not cheap," Becker said.