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)

Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

Cybermen patrol the National Museum of Scotland before the opening of the Doctor Who Worlds of Wonder exhibition in Edinburgh, Scotland on Wednesday, December 7, 2022. (Photo by Murdo MacLeod/The Guardian)

A baby of an internally displaced woman gets weighed during a doctor and nutritionist review to prevent malnutrition at a makeshift clinic in Ladan IDP camp, on the outskirts of Dollow, in Jubaland state, Somalia, 30 January 2024. (Photo by Daniel Irungu/EPA/EFE)

A woman wearing a protective mask is seen behind a girl dressed in a Plague Doctor Mask in Western-Ukrainian city of Lviv, Ukraine, 22 March 2020. Ukrainian Designer Anastasia Markovska sewed protective masks looking like Plague Doctor Masks, the traditional costume of Venice Carnival, for herself and her friends due to the ongoing pandemic of the COVID-19 disease caused by the SARS-CoV-2 coronavirus. In Ukraine had been 47 laboratory-confirmed cases of COVID-19, including three deaths and one recovery as Ukraine's Health Ministry announced. (Photo by Pavlo Palamarchuk/EPA/EFE)

Igor Armicach, a doctoral student at Hebrew University's Arachnid Collection, looks onto giant spider webs, spun by long-jawed spiders (Tetragnatha), covering sections of the vegetation along the Soreq creek bank, near Jerusalem, Israel on November 7, 2017. (Photo by Ronen Zvulun/Reuters)

Christian families living in a refugee camp stand under a tree in Kaga-Bandoro, Central African Republic, Tuesday February 16, 2016. Refugees in the north of Central African Republic say they hope the new president will bring peace but no one is heading home just yet. Thousands are still living in displacement camps in Kaga-Bandoro, a stronghold of the former Muslim rebel group known as Seleka that was in power for nearly a year. The one-time rebels say they are waiting to see how the election turns out before taking any action. (Photo by Jerome Delay/AP Photo)