It won't save the world, or end global climate change.

It won't reduce our carbon footprint, or eliminate our dependence on fossil fuels.

But it might make us see that such things are possible.

All we need do is turn out non-essential lighting and electronics for one hour tonight, between 8 and 9 p.m.

Millions of other people around the world are expected to do the same. It's an effort known as Earth Hour (earth hour.org), designed to promote energy conservation and sustainability.

The event, initiated by the World Wildlife Fund in Sydney last year, has drawn the participation of nearly 200 cities around the world, according to the Web site.

Honolulu has joined the bandwagon. The Honolulu Advertiser is a co-sponsor, along with the City and County of Honolulu and others. Mayor Mufi Hannemann called it "an opportunity for people to show that they have the power to work together to make a difference."

That's no small point. On an island that depends on fossil fuels for about 90 percent of its energy, we obviously need to do something different.

And even a symbolic gesture like Earth Hour can have have positive effects, especially on impressionable children. They'll want to know why they're sitting in the dark; it's a chance to teach them the importance of reducing our energy consumption and creating a more sustainable world.

After all, they're the ones who will inherit it.