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)

A woman whose livelihood depends on selling recyclable wastes collects trash from a dumping site while surrounded by Marabou storks on the outskirts of Uganda's capital Kampala March 31, 2015. (Photo by James Akena/Reuters)

A woman paints the floor of a pond as her child pulls at her saree in Delhi, India November 23, 2016. (Photo by Cathal McNaughton/Reuters)

A Los Angeles County Fire helicopter flies over during the “Skirball Fire” which began early morning in Bel-Air, California, USA, 06 December 2017. An outbreak of several fires North of Los Angeles has occurred as one of the strongest Santa Ana winds forecast of the season is ongoing and expected to last several days. (Photo by John Cetrino/EPA/EFE)

Zhao Deli waves as he pilots his self-made “flying scooter” in Dongguan, Guangdong Province, China, 12 August 2018 (issued 16 August 2018). Inspired by a cartoon he watched as a child, Zhao Deli sold off his apartment in pursuit of his dream of building a flying scooter. (Photo by Aleksandar Plavevski/EPA/EFE)

A girl lights a candle as she marks the anniversary of 2015 Nepal earthquake, at Boudhanath stupa in Kathmandu, Nepal April 25, 2017. (Photo by Navesh Chitrakar/Reuters)

A roadside ice-cream vendor waits for customers at a market in New Delhi, India, April 7, 2016. The Indian economy is characterized by the existence of a vast majority of informal or unorganized labor employment. (Photo by Altaf Qadri/AP Photo)

A child uses an umbrella to avoid rain falling on a fire at the northern Greek border point of Idomeni, Greece, Monday, April 25, 2016. Many thousands of migrants remain at the Greek border with Macedonia, hoping that the border crossing will reopen, allowing them to move north into central Europe. (Photo by Gregorio Borgia/AP Photo)