LONDON -- Europe's best known landmarks -- including the Eiffel Tower, Big Ben and Rome's Colosseum -- fell dark Saturday, following Sydney's Opera House and Beijing's Forbidden City in joining a global climate change protest, as lights were switched off across the world to mark the Earth Hour event.
Millions of people were turning off lights and appliances for an hour from 8:30 p.m. in a gesture to highlight environmental concerns and to call for a binding pact to cut greenhouse gas emissions. This year's was the fourth annual Earth Hour, organized by the World Wildlife Fund.
As each time zone reaches the appointed hour, skylines go dark and landmarks dim, from a Manila shopping mall to Berlin's Brandenburg Gate and the Empire State Building in New York.
Some 4,000 cities in more than 120 countries -- starting with the remote Chatham Islands off the coast of New Zealand -- voluntarily switched off Saturday to reduce energy consumption, though traffic lights and other safety features would be unaffected, organizers said.
''We have everyone from Casablanca to the safari camps of Namibia and Tanzania taking part,'' said Greg Bourne, CEO of World Wildlife Fund in Australia, which started Earth Hour in 2007 in Sydney before it spread to every continent.
In Katmandu, Nepal -- where electricity supplies aren't constant -- protesters unable to turn out lights held a candlelight vigil, while in the Maldives the state broadcaster ceased transmission for an hour to mark the event, WWF said.
Organizers hoped the event would put pressure on global lawmakers to push for clear progress on agreeing a binding international pact to reduce greenhouse gas emissions.
In Europe, Italy's Leaning Tower of Pisa and buildings across Germany and a host of nations went dark. Amsterdam cut the lights at most city buildings including Schiphol Airport, Artis Zoo and the Amsterdam Arena.