People holding candles mark Earth Hour after the lights are switched off in front of St. Basil Cathedral on Red Square in Moscow, Russia, Saturday, March 19, 2016. The participants said they also used the event to pay tributes to the victims of the Dubai plane crash in southern Russia that killed all 62 people aboard on Saturday. Cities around the world turned out the lights Saturday evening to mark the 10th annual Earth Hour, a global movement dedicated to protecting the planet and highlighting the effects of climate change. Lights went out for the hourlong event – from 8:30 p.m. to 9:30 p.m. local time – in Beijing, Moscow, Beirut, Cairo, Athens, Rome, and Paris. The lights atop the Empire State Building in New York were dimmed, and some billboards in Times Square also went dark. The first Earth Hour event was held on March 31, 2007, when the WWF conservation group inspired people in Sydney to turn out the lights for an hour. Since then, the WWF-organized event has expanded to thousands of cities and towns around the world and has been held every March. (Photo by Alexander Zemlianichenko/AP Photo)





This combo photo shows the Taipei 101 skyscraper with its lights on and off to mark Earth Hour in Taipei, Taiwan, Saturday, March 19, 2016. Cities around Asia were turning out the lights Saturday evening to mark the 10th annual Earth Hour, a global movement dedicated to protecting the planet and highlighting the effects of climate change. (Photo by Wally Santana/AP Photo)





This combination photo shows the Hyllie water tower lit, left, and with the lights turned off to mark Earth Hour in Malmo, Sweden, Saturday, March 19, 2016. (Photo by Johan Nilsson/TT News Agency via AP Photo)





In this two-picture combo, the Trevi fountain is seen at left with its light on, and at right with its lights off, on the occasion of the 10th annual Earth Hour, in Rome, Saturday, March 19, 2016. In several Italian cities officials switched off lights normally illuminating major monuments in a global movement dedicated to protecting the planet and highlighting the effects of climate change. (Photo by Giorgio Onorati/ANSA via AP Photo)





This two photo combination picture shows after and before lighting is switched off to mark Earth Hour, with the Kremlin, left, and st. Basil Cathedral, right, on Red Square in Moscow, Russia, Saturday, March 19, 2016. (Photo by Alexander ZemlianichenkoAP Photo)





This combination photo shows the Eiffel Tower before and after its lights were turned off to mark Earth Hour in Paris, France, Saturday, March 19, 2016. Cities around the world were turning out the lights Saturday evening to mark the 10th annual Earth Hour, a global movement dedicated to protecting the planet and highlighting the effects of climate change. (Photo by Kamil Zihnioglu/AP Photo)





In this two photo combination picture, the temple of the Parthenon is pictured before and after having its lighting switched off to mark the Earth Hour in Athens on Saturday, March 19, 2016. Individuals, businesses, cities, and landmarks around the world are switching off their lights for one hour on Saturday to focus attention on climate change. (Photo by Yorgos Karahalis/AP Photo)





The great Mosque of Muhammad Ali Pasha in the Citadel and the great Pyramids, in rear left, are illuminated before having the light switched off to mark Earth Hour, in Cairo, Egypt, Saturday, March 19, 2016. (Photo by Amr Nabil/AP Photo)





The great Mosque of Muhammad Ali Pasha in the Citadel and the great Pyramids, in rear left, are in darkness after having the main lighting switched off to mark Earth Hour, in Cairo, Egypt, Saturday, March 19, 2016. (Photo by Amr Nabil/AP Photo)





In this two photo combination picture, the government headquarters is shown before and after having its lighting switched off to mark Earth Hour in Beijing, Saturday, March 19, 2016. (Photo by Bilal Hussein/AP Photo)





Tourists kissing front of Malaysia's landmark Petronas Twin Towers with lights on before turned off to mark Earth Hour 2016 in Kuala Lumpur, Malaysia, 19 March 2016. Earth Hour takes place worldwide at 8.30 p.m. local time and is a global call to turn off lights for 60 minutes to raise awareness of the danger of global climatic change (Photo by Fazry Ismail/EPA)





A combination photograph shows the lights of the Sydney Opera House before (top) and after they were switched off for Earth Hour in Sydney, Australia, March 19, 2016. (Photo by David Gray/Reuters)





A combination photograph shows the financial district of Pudong before (top) and during Earth Hour in Shanghai, China, March 19, 2016. (Photo by Aly Song/Reuters)





A combination picture shows an overview of central Tokyo with the illuminated Tokyo Tower at the centre before (L) and during Earth Hour, when its lights were switched off, Japan, March 19, 2016. (Photo by Thomas Peter/Reuters)





Combination picture shows the Grand Palace before (top) and during Earth Hour in Bangkok, Thailand on March 19, 2016. (Photo by Jorge Silva/Reuters)





A combination photo showing a Garuda Maintenance Facility (GMF) hangar before (top) and during Earth Hour at Soekarno-Hatta airport near Jakarta, Indonesia, March 19, 2016. (Photo by Reuters/Beawiharta)





A combination photograph shows Georgia's Presidential Palace before (top) and during (bottom) Earth Hour in Tbilisi, Georgia, March 19, 2016. (Photo by David Mdzinarishvili/Reuters)





A combination photograph shows the lights of the Mir castle complex before (top) and after they were switched off for Earth Hour in the town of Mir, Belarus March 19, 2016. (Photo by Vasily Fedosenko/Reuters)





The Brandenburger Tor gate is seen before the Earth Hour in Berlin, Germany March 19, 2016. (Photo by Fabrizio Bensch/Reuters)





A combination picture shows the Sony Center at the Potsdamer Square before (top) and during Earth Hour in Berlin, Germany March 19, 2016. (Photo by Fabrizio Bensch/Reuters)





A combination photograph shows the Austrian Parliament before (top) and during Earth Hour in Vienna, Austria, March 19, 2016. (Photo by Heinz-Peter Bader/Reuters)





This combination picture shows the Houses of Parliament before (top) and after the lights were switched off for Earth Hour in London, Britain March 19, 2016. (Photo by Neil Hall/Reuters)





This combination picture shows the London Eye before (top) and after the lights were switched off for Earth Hour in London, Britain March 19, 2016. (Photo by Neil Hall/Reuters)





This combination picture shows Piccadilly Circus illuminated after (top) and during when the lights were switched off for Earth Hour in London, Britain March 19, 2016. (Photo by Neil Hall/Reuters)





This combination picture shows the Houses of Parliament before (L) and after the lights were switched off for Earth Hour in London, Britain March 19, 2016. (Photo by Neil Hall/Reuters)





A combination photo shows the “Puente Nuevo” (New Bridge) in the day (top), at night (C) and during Earth Hour in Ronda, near Malaga, southern Spain, March 19, 2016. (Photo by Jon Nazca/Reuters)





A combination photo shows the “Puente Nuevo” (New Bridge) in the day (top), at night (C) and during Earth Hour in Ronda, near Malaga, southern Spain, March 19, 2016. (Photo by Jon Nazca/Reuters)