Passengers check their mobile devices as a bin is full of garbage during a protest by the cleaning staff at Barcelona's airport, Spain, December 1, 2016. (Photo by Albert Gea/Reuters)

Dust covered seats are pictured inside the lounge of the Jaisalmer Airport in desert state of Rajasthan, India, August 13, 2015. Two-and-a-half years after the completion of a new $17 million terminal building, the airport in Jaisalmer, a small and remote desert city in India's western Rajasthan state, stands empty. (Photo by Anindito Mukherjee/Reuters)

Smoke billows from Jinnah International Airport in Karachi, Pakistan, June 9, 2014. (Photo by Athar Hussain/Reuters)

A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

A bus goes through a flooded area in Jiujiang, Jiangxi Province, China, June 19, 2016. A week of torrential rain in southern China has killed dozens of people and forced relocation of tens of thousands of residents, media reported. (Photo by Reuters/China Daily)

A man prepares tea at a roadside shop on a flooded street in Kolkata, India, August 11, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A resident removes mud on a street brought by monsoon rains in San Mateo, Rizal, Philippines, August 14, 2016. (Photo by Erik De Castro/Reuters)

Graffiti saying “justice” partially seen above flood waters in Asuncion, December 27, 2015. More than 100,000 people have had to evacuate from their homes in the bordering areas of Paraguay, Uruguay, Brazil and Argentina due to severe flooding in the wake of heavy summer rains brought on by El Nino, authorities said on Saturday. (Photo by Jorge Adorno/Reuters)