A Chinese man wears a mask to protect against pollution as he waits at a red light while commuting to work in heavy smog on December 8, 2015 in Beijing, China. The Beijing government issued a 'red alert' for the first time since new standards were introduced earlier this year as the city and many parts of northern China were shrouded in heavy pollution. Levels of PM 2.5, considered the most hazardous, crossed 400 units in Beijing, lower than last week, but still nearly 20 times the acceptable standard set by the World Health Organization. The governments of more than 190 countries are meeting in Paris to set targets on reducing carbon emissions in an attempt to forge a new global agreement on climate change. (Photo by Kevin Frayer/Getty Images)

A Brazilian drug gang member nicknamed Pilintra, 26, poses with a gun atop a hill overlooking a slum in Salvador, Bahia State, April 11, 2013. One of Brazil's main tourist destinations and a 2014 World Cup host city, Salvador suffers from an unprecedented wave of violence with an increase of over 250% in the murder rate, according to the Brazilian Center for Latin American Studies (CEBELA). (Photo by Lunae Parracho/Reuters)

A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

Lu Wei-ming (L), priest of the Wei-ming temple, and a worshipper burn a Taoist paper amulet during a prayer ritual at the temple in New Taipei city January 8, 2015. The shrine, down a narrow alleyway in a bustling district of the city, is dedicated to a deity who has watched over homosexuals for four centuries. Priest Lu founded the temple in 2006, at a time gays were excluded from most religious ceremonies. (Photo by Pichi Chuang/Reuters)

In this June 29, 2015 photo, hairdresser Loavia Bienaime, 30, sits on her bed as she prepares to begin her day in the room her family occupies in an government office building that was damaged in the 2010 earthquake in Port-au-Prince, Haiti. Bienaime's husband, Jimmy Bellefleur, used his skill as an electrician to connect the abandoned building to the power grid, and has repaired broken televisions, fans, and a blender for the family to use. (Photo by Rebecca Blackwell/AP Photo)

An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

Fans and community members gather around a LAPD car along the procession route for Nipsey Hussle after his memorial at the Staples Center in Los Angeles, California, April 11, 2019. 4 people shot and 1 dead during the procession LAPD reported on late April 11, 2019 The Grammy-nominated artist was killed in front of The Marathon Clothing store he founded in 2017. (Photo by Kyle Grillot/AFP Photo)

Israelis take cover as a siren sounds a warning of incoming rockets fired from the Gaza Strip, in Ashkelon, southern Israel, Sunday, May 16, 2021. (Photo by Heidi Levine/AP Photo)