Revellers take part in an annual block party before Carnival in downtown Rio de Janeiro, Brazil, January 16, 2016. The Rio de Janeiro Carnival will be held from February 5 to February 9. (Photo by Pilar Olivares/Reuters)

A history enthusiast, dressed as a soldier, fights during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna December 5, 2015. Hundreds of history enthusiasts gathered near the city of Slavkov before a re-enactment of Napoleon's famous battle of Austerlitz on Saturday to mark its 210th anniversary. (Photo by David W. Cerny/Reuters)

Six-month old female liliger cub Eva plays in snow with her mother Zita in the Zoo in Novosibirsk, Russia, Thursday, December 5, 2013. The cub's mother is Zita, a liger – half-lioness, half-tiger, and its father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

Swimmers climb out of a pool carved into the thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2014. According to organisers, about 700 swimmers across China took part in the event on the official launch day of the Harbin Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

This photo taken on April 5, 2013 shows Buddhist monks passing a yak in Seda Monastery, the largest Tibetan Buddhist school in the world, with up to 40,000 monks and nuns in residence for some parts of the year. Seda, known to Tibetans as Serthar is located in Ganzi prefecture in the west of China's Sichuan province and has become a hotbed of protests and violence since the Tibetan uprisings of March 2008. (Photo by Peter Parks/AFP Photo)

“A dirty thunderstorm (also, Volcanic lightning) is a weather phenomenon that occurs when lightning is produced in a volcanic plume. Dirty thunderstorms have been reported in Chile above the Chaiten Volcano, above Alaska's Mount Augustine volcano, and Iceland's Eyjafjallajökull volcano”.

Photo: A cloud of ash pours from Puyehue volcano in southern Chile, at sunset on June 5, 2011. (Claudio Santana/AFP)

The goats are known to be good climbers, but this one is taking the climbing thing to a whole new level. It clambered on the tip of its owner’s stick, as a part of the roadside performance for a quick coin, on the outskirts of Faisalabad, Pakistan, November 5, 2012. (Photo by Fayyaz Hussain/Reuters)

A riot policeman punches Greek photojournalist Tatiana Bolari during a demonstration in Athens' Syntagma (Constitution) square October 5, 2011. Police officers attacked several members of the press covering protests, injuring at least two members of the media. (Photo by Yannis Behrakis/Reuters)