Europe's best known landmarks¹ - 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.

上周六，世界各地纷纷熄灯响应“地球一小时”、抵御全球气候变化的活动。悉尼歌剧院、北京故宫，以及埃菲尔铁塔、大本钟和罗马圆形大剧场等欧洲著名地标建筑相继熄灯。

Manhattan lost some of its usual glow (left) late Saturday as millions around the world turned off lights and appliances for an hour.

In the United States, the lights went out（熄灭，离开） at the Empire State Building in New York, the National Cathedral in Washington, and the Coca-Cola headquarters in Atlanta.

Millions were expected to turn off lights and appliances for an hour from 8:30 pm in a gesture to highlight environmental concerns and to call for a binding²（捆绑的，有约束力的） pact³ to cut greenhouse gas emissions⁴. This year's was the fourth annual Earth Hour, organized by the World Wildlife Fund.

"I think it's great to see that hundreds of millions of people share this common value of lowering our carbon footprint（谈排放量） ," said Dan Forman, a spokesman for WWF in Washington.

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 were unaffected, organizers said.

"We have everyone from Casablanca to the safari⁵（旅行，狩猎远征） camps of Namibia and Tanzania taking part," said Greg Bourne, CEO of WWF in Australia, which started Earth Hour in 2007 in Sydney before it spread to every continent.

"It's saying to our politicians - you can't give up on climate change," said WWF spokeswoman Debbie Chapman in the UK.

Buckingham Palace and the British Parliament building went dark to support the campaign, along with other famed London landmarks including St. Paul's Cathedral and the Royal Albert Hall, as well as Edinburgh Castle in Scotland.

Moscow's iconic and imposing⁶ State University, perched（栖息） on a hill overlooking the city, all but disappeared into the darkness as the city took part in the protest. The gigantic Luzhniki Stadium nearby also went black, as did the skyscraping Ukraina Hotel downtown. Restaurants in Vladivostok held a so-called Candle Evening, promoting Earth Hour as a chance for romance.

Researchers at the Davis Station, in Antarctica, also joined the campaign - shutting off lights at the base.

Last year, some 88 cities took part in Earth Hour, which is backed by the United Nations as well as global corporations, nonprofit groups, schools, scientists and celebrities⁷.