Thanks to our position in the world, New Zealand was the fir' />

New Zealand's power consumption dropped 3.5 per cent during last night's Earth Hour.

Thanks to our position in the world, New Zealand was the first country to "power down" for an hour as part of the global initiative to highlight the threat of climate change.

The Chatham Islands kicked off the event by switching off its diesel generators. Soon after, the exterior lights of Auckland's Sky Tower, were turned off.

Time zone by time zone, nearly 4000 cities and towns in 88 countries joined the event sponsored by the World Wildlife Fund to dim non-essential lights from 8.30pm to 9.30pm.

From Scott Base in Antarctica to the Pyramids in Egypt, the Eiffel Tower and beyond, the world switched off lights and unnecessary appliances, dimming skyscrapers, streets and some of the world's most recognisable monuments.

Most major cities in New Zealand made a contribution, switching off lighting in streets and major buildings.

Events were held to mark Earth Hour, including a free concert in Christchurch's Cathedral Square and an informal celebration with candles in Queenstown.

National grid operator Transpower said part of the drop-off in power use compared with last week, could have been attributed to warmer weather but Earth Hour "would definitely have contributed".

Increased support for the second 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.