A combination picture shows the Sydney skyline before (top) and after the lights were turned off for Earth Hour March 28, 2009.

Lights went out at tourism landmarks¹ and homes across the globe on Saturday for Earth Hour 2009, a global event designed to highlight the threat from climate change.

From the Sydney Opera House and Harbour Bridge to the Eiffel Tower in Paris and London's Houses of Parliament, lights were dimmed as part of a campaign to encourage people to cut energy use and curb² greenhouse gas emissions³ from fossil fuels.

Organizers said the action showed millions of people wanted governments to work out a strong new U.N. deal to fight global warming by the end of 2009, even though the global economic crisis has raised worries about the costs.

"We have been dreaming of a new climate deal for a long time," Kim Carstensen, head of a global climate initiative at the conservation group WWF, said in a candle-lit bar in the German city of Bonn, which hosts U.N. climate talks between March 29 and April 8.

"Now we're no longer so alone with our dream. We're sharing it with all these people switching off their lights," he said.

The UN Climate Panel says greenhouse gas emissions are warming the planet and will lead to more floods, droughts, heatwaves, rising sea levels and animal and plant extinctions.

World emissions have risen by about 70 percent since the 1970s.

Australia first held Earth Hour in 2007 and it went global in 2008, attracting 50 million people, organizers say. WWF, which started the event, is hoping one billion people from nearly 90 countries will take part.

2009年“地球一小时”活动于上周六举行，当晚，世界各地的旅游标志性建筑和家家户户纷纷熄灯响应该活动。“地球一小时”是一项全球范围的活动，旨在让人们意识到气候变化的威胁。

作为号召人们节能减排努力的一部分，当晚，从悉尼歌剧院、海港大桥到巴黎的埃菲尔铁塔和伦敦的英国国会大厦，熄灯行动在全球接力。

活动主办方称，这一行动表明很多人希望到今年年底政府能合作制订一个强有力的、应对全球变暖的联合国新章程——尽管全球经济危机加剧了有关成本的担忧。

自然保护组织世界自然基金会（WWF）全球气候项目的负责人Kim Carstensen在德国波恩市的一个用蜡烛照明的酒吧里接受采访。他说：“我们期盼出台应对气候变化的新协议已经很久了。” 联合国气候变化峰会于本月29日至下月8日在德国波恩举行。

他说：“现在我们不再是一个人战斗。所有响应地球一小时活动的人和我们有着同一个梦想。”

联合国气候变化工作小组称，温室气体排放造成地球温度升高，并会导致洪涝、干旱、酷暑、海平面升高以及动植物灭绝等一系列生态问题。

自上世纪70年代以来，全球温室气体排放量增长了约70%。

据活动主办方介绍，“地球一小时”于2007年率先在澳大利亚举行，2008年发展为一项全球性的活动，当年共吸引了5千万人参加。该活动由世界自然基金会发起，目标是全球近90个国家的10亿人能参与“地球一小时”活动。