Visitors look at graffiti art created by Brazilian artist Image during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. The month-long event features the work of more than 60 street artists, representing 11 countries. (Photo by Andre Penner/AP Photo)

Villagers walk over a tree felled by rain in the village of Punta Caimanes, a place affected by heavy rains in the Izabal region, near Guatemala City, August 8, 2015. Heavy rains have affected eight communities in the municipality of El Estor and five in Livingston, both located in the region of Izabal, with five deaths due to floods, according to local media. (Photo by Josue Decavele/Reuters)

A man takes a dip inside a chapel during celebrations of the Orthodox Christian feast of Epiphany in Saint Petersburg, Russia on January 19, 2020. (Photo by Anton Vaganov/Reuters)

A woman stands in the middle of her fire damaged clothes after a massive fire at a market in Port-au-Prince, Haiti, Monday March 20, 2017. The fire raged at the biggest central market in the center of the Capital. (Photo by Dieu Nalio Chery/AP Photo)

Refugees and migrants try to find a place on an already full train headed for Serbia, near the city of Gevgelija, The Former Yugoslav Republic of Macedonia, on February 24, 2016. Refugees and migrants from Iraq and Syria continue to pass through Macedonia on their way to the European Union. (Photo by Georgi Licovski/EPA)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

A woman runs while another woman ducks down to avoid teargas as police disperse supporters of the opposition Coalition for Reforms and Democracy (CORD), led by former Prime Minister Raila Odinga, during a demonstration against Independent Electoral and Boundaries Commission (IEBC) in downtown Nairobi, Kenya, 09 May 2016. (Photo by Dai Kurokawa/EPA)

Visitors wear shirts with an image of former Chinese leader Mao Zedong at the Shanghai World Expo site in Shanghai, May 2, 2010. (Photo by Aly Song/Reuters)