The Boeoegg, a giant symbolic snowman made of wadding and and filled with firecrackers burns on top of a bonfire in Sechselaeuten square on April 24, 2017 in Zurich. When the bells of the Saint Peter's church chime six o'clock, the bonfire under the snowman is set in fire and the guildsmen wearing historical costumes ride around the bonfire. The faster the head of the snowman explods the warmer and more beautiful the summer will be. (Photo by Michael Buholzer/AFP Photo)

Visitors and a dog stand on the new “Skywalk” viewing platform on the Sonnenstein mountain in the Eichsfeld region near Bad Lauterberg im Harz, central Germany, on May 22, 2017. (Photo by Martin Schutt/AFP Photo/DPA)

This picture taken with an underwater camera shows Japan' s Yumi Adachi competing in the Mixed Duet technical final during the synchronised swimming competition at the 2017 FINA World Championships in Budapest, on July 17, 2017. (Photo by Bernadett Szabo/Reuters)

Women are covered in dust after making it out of a building that collapsed after an earthquake in the Roma neighborhood of Mexico City, Tuesday, September 19, 2017. A powerful earthquake shook Mexico City on Tuesday, causing panic among the megalopolis' 20 million inhabitants on the 32nd anniversary of a devastating 1985 quake. The US Geological Survey put the quake's magnitude at 7.1 while Mexico's Seismological Institute said it measured 6.8 on its scale. The institute said the quake's epicenter was seven kilometers west of Chiautla de Tapia, in the neighboring state of Puebla. (Photo by Rebecca Blackwell/AP Photo)

In this photo taken Wednesday, December 5, 2018, a woman who scavenges recyclable materials from garbage for a living is seen through a cloud of smoke from burning trash, surrounded by Marabou storks who feed on the garbage, at the dump in the Dandora slum of Nairobi, Kenya. As the world meets again to tackle the growing threat of climate change, how the continent tackles the growing solid waste produced by its more than 1.2 billion residents, many of them eager consumers in growing economies, is a major question in the fight against climate change. (Photo by Ben Curtis/AP Photo)

Children walk past the partially collapsed boundary wall of a school and a Buddhist shrine that were damaged during the earthquake earlier this year at Khumjung, a typical Sherpa village in Solukhumbu district also known as the Everest region, in this picture taken November 30, 2015. (Photo by Navesh Chitrakar/Reuters)

A man demonstrates outside Republican presidential candidate Donald Trump's news conference at Trump Tower in New York, U.S., May 31, 2016. (Photo by Shannon Stapleton/Reuters)

A fighter belonging to Jaish al-Islam (Islam Army) runs to take cover near the frontline on March 14, 2016 in the neighbourhood of Jobar, on the eastern outskirts of the capital Damascus. (Photo by Amer Almohibany/AFP Photo)