About 20 Chinese cities joined a worldwide relay on Saturday night to switch off lights of major buildings for one hour to highlight concerns about climate change while calling for actions.

上周六晚上全中国有二十多个城市参加了全球性的应对气候变化，城市主要建筑物熄灯一小时的活动。

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"In hotels, switch off lights and re-use linens, " advises Chan.

BBC: Sustainable travel in Malaysia

The Kremlin due to switch off its lights at 16:30 GMT along with 90 other landmark buildings in Moscow.

BBC: Sydney dims down for Earth Hour climate change protest

It encourages cities and individuals to switch off non-essential lights for an hour at 20:30 local time.

BBC: Sydney dims down for Earth Hour climate change protest