A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

A masked reveller parades through the streets on the first day of the carnival season in Lucerne, Switzerland, 12 February 2015. In the background the well known Kappellbruecke bridge. (Photo by Alexandra Wey/EPA)

Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

Crowds watch surfers as the first big swell of the year arrives in Nazaré, Portugal on October 28, 2015. (Photo by Pedro Miranda/Demotix/Corbis)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)

Afghan protesters beat a policeman after a suicide attack that targeted crowds of minority Shiite Hazaras during a demonstration at the Deh Mazang Circle of Kabul on July 23, 2016. Islamic State jihadists claimed responsibility for twin explosions July 23 that ripped through crowds of Shiite Hazaras in Kabul, killing at least 61 people and wounding 207 others in apparently their deadliest attack in the Afghan capital. The bombings during a huge protest over a power transmission line could deepen sectarian divisions in a country well known for communal harmony despite decades of war. (Photo by Wakil Kohsar/AFP Photo)

Nine-year-old Barry Miller appears none too impressed with the movements of an African Rock Python which is exploring his scalp. (Photo by Keystone/Getty Images). 27th August 1961

A man stands next to a barricade blocking a road during a protest calling on the government to help ease the economic effects of an harmful algal bloom that had affected their livelihoods at Chiloe island in Chile, May 6, 2016. (Photo by Pablo Sanhueza/Reuters)