About Earth Hour On March 31 2007,for one hour,Sydney made a powerful statement about the greatest contributor to global warming – coal-fired electricity – by turning off its lights.Over 2.2 million Sydney residents and over 2,100 businesses switched off,leading to a 10.2% energy reduction across the city.What began as one city taking a stand against global warming caught the attention of the world.In 2008,24 global cities participated in Earth Hour at 8pm on March 29.Earth Hour is the highlight of a major campaign to encourage businesses,communities and individuals to take the simple steps needed to cut their emissions on an ongoing basis.It is about simple changes that will collectively make a difference – from businesses turning off their lights when their offices are empty,to households turning off appliances rather than leaving them on standby.地球1小時事件 全段翻譯 一個工人緊緊抓住悉尼港的一個形狀似電燈泡的32米的熱氣球,以宣傳地球1小時事件.