A woman is tattooed by an artist during Warsaw Tattoo Convention 2014 in Warsaw November 29, 2014. (Photo by Kacper Pempel/Reuters)

A man smokes marijuana during a demonstration in support of the legalization of marijuana in Medellin, May 2, 2015. (Photo by Fredy Builes/Reuters)

Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

Pilgrims lift up their dresses as they cross the Quema river during the annual El Rocio pilgrimage in Villamanrique, near Sevilla on June 1, 2017. El Rocio pilgrimage is the largest in Spain with hundreds of thousands of devotees wearing traditional outfits converging in a burst of colour as they make their way on horseback and decorated carriages across the Andalusian countryside. (Photo by Cristina Quicler/AFP Photo)

An incredible clear-air lightning display from storms to the east of Noonamah, just outside Darwin on April 6, 2015. (Photo by Jacci Ingham/The Guardian)

Filipino beauty candidates hide from the sun before a group photo during the media presentation of the Miss Philippines Earth 2017 held at a hotel in Manila, Philippines, 05 July 2017. A total of 40 environmentally aware and concerned Filipino young ladies will compete to represent the Philippines at the Miss Earth beauty pageant. Miss Earth is a pioneering beauty pageant that serves as a vehicle for environmental advocacy. (Photo by Mark R. Cristino/EPA)

Pamukkale, Turkey, is home to these terrace pools, formed by the build-up of carbonate mineral from the warm water flowing from the thermal springs above. (Photo by Image Courtesy of Jennifer Hayes/Getty Images)

A boat sails behind a woman looking through binoculars as she sits on a cliff on a sunny day in Sydney, Australia, May 29, 2016. (Photo by David Gray/Reuters)