This photo taken on March 22, 2025 shows the Big Ben during the Earth Hour event in London, Britain. Photo: Xinhua

This photo taken on March 22, 2025 shows the Piccadilly Circus electronic billboard before the Earth Hour event in London, Britain. Photo: Xinhua

This photo taken on March 22, 2025 shows the Tower Bridge during the Earth Hour event in London, Britain. Photo: Xinhua

This combo photo taken on March 22, 2025 shows the Big Ben before (L) and during the Earth Hour event in London, Britain. Photo: Xinhua

This photo taken on March 22, 2025 shows the Piccadilly Circus electronic billboard during the Earth Hour event in London, Britain. Photo: Xinhua