Ever since WWF asked Sydney residents and government officials to turn out the lights for an hour in 2007, critics and fans have debated the merits of the publicity stunt, called Earth Hour, which is meant to draw attention to energy use. This year’s event is scheduled for Saturday at 8:30pm local time, all over the world.

Astronomers think it’s a great idea, of course, because it dovetails nicely with their dark-sky campaigns. And major tourist attractions in cities around the world have jumped on the bandwagon.

But others, including climate change skeptic Bjorn Lomberg, point out that the campaign, with its widespread advertising, could actually have an emissions footprint that outweighs the energy that would have been spent during Earth Hour.

One Earth Hour promotional campaign at a Malaysian shopping mall has drawn attention for offering tickets to an F1 race event to patrons spending over 1,000 ringgit (US$277) that day. F1 races are considered one of the most emissions-heavy sporting events, according to Reuters, which carried the story.

Unshaken, a WWF spokesperson told eWeek that “It is not about how much energy is saved, it is meant to be a symbolic gesture to global leaders about climate change.”

Image: Your Light Switch Is Your Vote by Shepard Fairey under creative commons.