Wellington - People switched off their lights in 44 cities and towns throughout New Zealand at 8:30 pm (0830 GMT) Saturday to kick off the worldwide 2008 Earth Hour event designed to draw attention to global warming.

If hopes of the organizers, the World Wide Fund for Nature (WWF), are realized, by the time the hour from 8:30 to 9:30 pm local time has passed around the globe, 1 billion people in more than 1,000 cities would have spent 60 minutes in darkness to show their concern about the excessive use of energy and its impact on the environment.

The event has gathered support since it was launched in 2007 in Sydney, where 2.2 million homes and businesses chose an hour of voluntary darkness.

Last year, this spread to an estimated 50 million people around the world, with global landmarks - including the Golden Gate Bridge in San Francisco, Rome's Colosseum and the Coca Cola billboard in New York's Times Square - all blacked out.

In New Zealand last year, only the South Island city of Christchurch took part with an estimated 3 per cent of its population flicking off their switches.

A nationwide effort this year saw the country's tallest building, the Sky Tower in Auckland, which alone uses the equivalent of 1,600 light bulbs, and the landmark Beehive, executive wing of the national Parliament in Wellington, plunged into darkness.

Local organizer Dairne Poole admitted it was largely symbolic but said Earth Hour sent a message that people cared about climate change. (dpa)