WWF hopes thesecond Earth Hour will involve up to a billion people across the globe.
WWF hopes thesecond Earth Hour will involve up to a billion people across the globe.
Support for Earth Hour has "exploded" both in New Zealand and globally, says conservation group WWF.
New Zealand will lead the way tonight as, time zone by time zone, the world "powers down" in support of the climate change event.
WWF hopes this second Earth Hour can become the biggestglobal voluntary action the world has seen, involving up to a billion people across the globe.
"There's no better place for Earth Hour 2009 to start than New Zealand," said WWF New Zealand project director Dairne Poole.
Thousands of homes and businesses throughout the country are joining in the initiative, by turning off lights and non-essential appliances between 8.30pm and 9.30pm.
Seven times more municipalities globally have signed on since last year's Earth Hour, which drew participation from 400 cities after Sydney, Australia, held a solo event in 2007.
By plunging cities and towns into darkness, Earth Hour illustrated the power of collective action to reduce energy use and carbon emissions, said New Zealand's Energy Efficiency and Conservation Authority chief executive Mike Underhill.
Events are being held throughout the country as part of Earth Hour. They include a free concert in Christchurch's Cathedral Square and an informal celebration with candles in Queenstown.
Some councils will be handing out energy-efficient lightbulbs.
New Zealand's 26-member winter team at Antarctica's Scott Base will even be doing their bit, shutting down to minimum safety lighting and switching off all unnecessary appliances and computers.
Across the rest of the world, lights will be dimmed on great monuments such as Egypt's Pyramids, the Acropolis in Athens, the Eiffel Tower in Paris and Chicago's Sears Tower.
In all, 84 countries are taking part.
Earth Hour comes as United States president Barack Obama calls for a politically viable new global climate deal that avoids the fate of the Kyoto Protocol, which failed to win US domestic support.
Negotiations are planned on a new global warming treaty in Denmark this December. The Kyoto Protocol is set to expire in 2012.
