Revelers dance at a Jacarezinho samba school practice session ahead of Carnival celebrations on February 16, 2014 in Rio de Janeiro, Brazil. The Jacarezinho “favela” was previously controlled by drug traffickers and is now occupied by the city's Police Pacification Unit (UPP). Carnival officially begins February 28, but pre-Carnival celebrations are already underway. (Photo by Mario Tama/Getty Images)

A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

Members of the samba school of the Grupo Especial Independencia Tricolor participate in the carnival celebration at the Anhembi sambodrome in Sao Paulo, Brazil, 09 February 2018. (Photo by Sebastiao Moreira/EPA/EFE)

The North Side Skull & Bone Gang stand together during the wake up call for Mardi Gras, Tuesday, February 9, 2016, in New Orleans. Their costumes are intended to represent the dead and they bring a serious message, reminding people of their mortality and the need to live a productive and good life. (Photo by Brynn Anderson/AP Photo)

Crowds supporting the Same Sеx Marriage Survey listen to politicians and advocates at Taylor Square in the heart of Sydney's gay precinct on November 15, 2017 in Sydney, Australia. Australians have voted for marriage laws to be changed to allow same-sеx marriage, with the Yes vote claiming 61.6% to to 38.4% for No vote. Despite the Yes victory, the outcome of Australian Marriage Law Postal Survey is not binding, and the process to change current laws will move to the Australian Parliament in Canberra. (Photo by James Alcock/Getty Images)

Kale grows at Kajodlingen farm in Gothenburg, Sweden, September 28, 2016. They are doing it on the rooftops, on tower block balconies and even on a disused railway: Swedes have discovered a passion for urban gardening as a way of growing fresh food and getting back in touch with nature. Part of a global movement, an increasing number of Swedish city-dwellers are growing their own in window boxes and allotments or are visiting public gardens built in or on industrial or office spaces. (Photo by Maxim Shemetov/Reuters)