Photos: The world goes dark for Earth Hour

Earth Hour swept the globe Saturday, with people and businesses urged to turn off the lights from 8:30 p.m. to 9:30 p.m. local time.

Chicago was named the 2014 US Earth Hour capital in honor of the city’s efforts to fight climate change. Chicagoans are urged to flip off the power tonight for one of the world’s largest environmental awareness events.

Learn more at EarthHour.org.

Earth Hour celebrated around the world

The Serbian National Assembly building in Belgrade. | Andrej Isakovic/Getty Images

The lights of Cologne, Germany switch off Saturday. | Outhenning Kaiser/Getty Images

The Temple of Parthenon in Greece goes dark. | Aris Messinis/Getty Images

The House of Parliament in London during Earth Hour. | Carl Court/Getty Images

People light candles in Bucharest during an Earth Hour celebration. | Daniel Mihailescu/Getty Images

St Peter’s Basilica in the Vatican switches the lights off. | Tiziana Fabitiziana/Getty Images

The Azadi Tower in Tehran, Iran goes dark. | Ebrahim Noroozi/AP Photo

Red Square becomes the Dark Square in Moscow. | Yuri Kadobnovyuri/Getty Images

The lights switch off at the Petronas Towers in Malaysia. | Ed Jones/Getty Images