A dead red-tailed monkey hangs by its tail above the ground, in order to keep it away from ants, in the forest near the city of Mbandaka, Democratic Republic of the Congo, April 5, 2019. Bushmeat hunters are emptying Central Africa's forests at a high rate, researchers say. A growing appetite for wild meat in cities has ramped up the scale of hunting. Research shows around 6 million tonnes of bushmeat are sourced annually from the Congo Basin, whose forest spans across six countries and is second in size only to the Amazon. (Photo by Thomas Nicolon/Reuters)

The main church in the town of San Damian Texoloc, Mexico stands in front of the Popocatepetl volcano as is spews ash and vapor early Tuesday, July 9, 2013. Last Saturday, Mexico's National Center for Disaster Prevention raised the volcano alert from Stage 2 Yellow to Stage 3 Yellow, the final step before a Red alert, when possible evacuations could be ordered after the Popocatepetl volcano spit out a cloud of ash and vapor 2 miles (3 kilometers) high over several days of eruptions. (Photo by J. Guadalupe Perez/AP Photo)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

Vehicles clog a highway during a hazy day in Beijing, China, Wednesday, February 26, 2014. Beijing remained cloaked in hazardous white pollution hiding much of its skyline Wednesday, despite the announced closures or production cuts at 147 of the city's industrial plants. (Photo by Ng Han Guan/AP Photo)

Two women look at a mobile phone as they stand on Tiananmen Square during a sand storm in heavily polluted weather in Beijing on February 28, 2013. Beijing residents were urged to stay indoors as pollution levels soared before a sandstorm brought further misery to China's capital. (Photo by Ed Jones/AFP Photo)

Participants try to cover themselves from color powder sprayed by volunteers as they run through a “color station” during a five-kilometer color run event held in Beijing, China Saturday, June 21, 2014. (Photo by Andy Wong/AP Photo)

A vehicle leaves light trails in a long exposure photograph as it drives beneath the 500-metre Aperture Spherical Radio Telescope in Pingtang county, China. Construction on the device began in 2011 and is nearing completion. (Photo by Liu Xu/AP Photo)

A woman takes a selfie in front of a sculpture of a rooster that local media say bears resemblance to U.S. President-elect Donald Trump, outside a shopping mall in Taiyuan, Shanxi province, China December 30, 2016. (Photo by Jon Woo/Reuters)