Fireworks explode over Elizabeth Tower housing the Big Ben clock in London. (Photo by Kirsty Wigglesworth/Associated Press)

A little blue penguin which was found at Papamoa Beach, covered in oil after the Liberian cargo ship, Rena, hit a reef, on October 7, 2011, in Tauranga, New Zealand. Reports of an oil sheen have been spotted on the surface of the water surrounding the ship and two penguins have been found covered in oil. (Photo by SUNLIVE New Zealand/Getty Images)

Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

Performers eat their lunch before the start of the New Year's Day Parade in London, January 1, 2016. (Photo by Kevin Coombs/Reuters)

People cheer as the ball drops at midnight in Times Square on January 1, 2015 in New York City. An estimated one million people from around the world are expected to pack Times Square to ring in 2015. (Photo by Andrew Theodorakis/Getty Images)

Members of a Chinese opera take a selfie before a performance at a shopping mall ahead of the Chinese Lunar New Year celebrations in Bangkok, Thailand, February 4, 2016. (Photo by Athit Perawongmetha/Reuters)

A man wears a costume during a parade to celebrate the Chinese Lunar New Year, which welcomes the Year of the Monkey, in Madrid, Spain, February 13, 2016. (Photo by Andrea Comas/Reuters)

A Tibetan man stirs butter tea made for the arriving guest during the function organised to mark Losar or the Tibetan New Year at a Tibetan Refugee Camp in Lalitpur February 19, 2015. Tibetans across the world marked the arrival of the New Year with prayers and festivities. (Photo by Niranjan Shrestha/AP Photo)