The Eiffel Tower has gone dark briefly, with lights going out to mark Earth Hour, the campaign to raise awareness about climate change.

The five-minute dark-out on Saturday night was a symbolic gesture in the City of Light.

France has been preparing for months to host an international climate conference in Paris at the end of the year, pressing nations to set attainable goals for reducing greenhouse gases and mobilizing international finances to fight climate change.

Earth Hour was launched in 2007 by the World Wildlife Fund to encourage awareness of environmental issues. The idea is to turn off lights for an hour — not possible for safety reasons for the Eiffel Tower.