A man lights lamps to form the number 60, representing the 60 minutes of Earth Hour, during Earth Hour in Colombo, Sri Lanka March 25, 2017. REUTERS/Dinuka Liyanawatte

Dayan Pagoda is seen during Earth Hour in Xi'an, Shaanxi province, China, March 25, 2017. Picture taken March 25, 2017. REUTERS/Stringer

A view of China Central Radio and Television Tower during Earth Hour in Beijing, China March 25, 2017. REUTERS/Jason Lee

The area around Selamat Datang Monument, also referred to as the Bunderan HI roundabout, is pictured before Earth Hour in Jakarta, Indonesia March 25, 2017. REUTERS/Darren Whiteside

The Eiffel Tower is pictured before Earth Hour in Paris, France, March 25, 2017, at which lights are switched off around the world at 8:30 p.m. on Saturday evening to mark the 10th annual Earth Hour and to draw attention to climate change. REUTERS/Philippe Wojazer

A tourist junk sails past as most of the lights in buildings in the financial Central District are switched off during Earth Hour in Hong Kong, China March 25, 2017. REUTERS/Bobby Yip

The area around Selamat Datang Monument, also referred to as the Bunderan HI roundabout, is pictured after the lights were switched off for Earth Hour in Jakarta, Indonesia March 25, 2017. REUTERS/Darren Whiteside

The Tokyo Tower is seen after its lights were switched off for Earth Hour in Tokyo, Japan March 25, 2017. REUTERS/Issei Kato

The Sydney Opera House seen during the tenth anniversary of Earth Hour in Sydney, Australia, March 25, 2017. REUTERS/David Gray

The Bund on the banks of the Huangpu River is pictured before Earth Hour in Shanghai, China March 25, 2017. REUTERS/Aly Song

A combination photo shows the Tokyo Tower before (L) and after its lights were switched off for Earth Hour in Tokyo, Japan March 25, 2017. REUTERS/Issei Kato

Glasses with lights lamps form the number 60, representing the 60 minutes of Earth Hour, during Earth Hour in Makati city, metro Manila, Philippines March 25, 2017. REUTERS/Romeo Ranoco

A view shows the Kremlin during Earth Hour in central Moscow, Russia, March 25, 2017. REUTERS/Maxim Shemetov

Star Wars enthusiasts raise their lightsabers as they participate in the annual Earth Hour, an hour of lights out to raise awareness on climate change, in Taguig city, metro Manila, Philippines March 25, 2017. REUTERS/Romeo Ranoco

Shopping malls are seen during Earth Hour in Nanjing, Jiangsu province, China, March 25, 2017. Picture taken March 25, 2017. REUTERS/Stringer