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)

In this Thursday, December 1, 2016 photo, Cat Bigney, part of the Oglala Native American tribe, waits on the shore of the Cannonball river for travelers to arrive by canoe at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D. So far, those at the camp have shrugged off the heavy snow, icy winds and frigid temperatures. But if they defy next week's government deadline to abandon the camp, demonstrators know the real deep freeze lies ahead. Life-threatening wind chills and towering snow drifts could mean the greatest challenge is simple survival. (Photo by David Goldman/AP Photo)

People take part in a protest outside the Department for Education, London, Sunday August 16, 2020, in response to the A-level results. The British government has been urged to “get a grip” over how grades are being awarded to school students, who were unable to take exams earlier this summer because of the coronavirus pandemic. The latest confusion emerged late Saturday when England’s exam regulator launched a review on its own just-published guidance on how students can appeal grades awarded under a complicated system. (Photo by London News Pictures/The Sun)

Rows of workers shelter under umbrellas from the scorching heat as they painstakingly sort through a red carpet of millions of chilli peppers in Bogra, Bangladesh on October 3, 2023. They sort the rotten and broken chilli peppers out to separate the poor quality ones which won't sell. In a line, the pickers who are paid less than £3 for a 10-hour shift slowly move forward with their baskets to separate the bad from the good after the chilies have been dried in the sun for a week. (Photo by Joy Saha/Rex Features/Shutterstock)

Myanmar punks walk in the downtown area as they take part in a punk gathering ahead of the Thingyan water festival in Yangon, Myanmar, 12 April 2017. Myanmar punks have been gathering in Yangon on the day ahead of Thingyan water festival to celebrate every year. The annual water festival is marked with large groups of people congregating to celebrate by splashing water and throwing powder at each others faces as a symbolic sign of cleansing and washing away the sins from the old year to mark the traditional New Year in countries such as Myanmar, Thailand, Laos and Cambodia. This year, the Myanmar Thingyan water festival falls on 13 April and ends on 16 April. (Photo by Lynn Bo Bo/EPA)

People collect water from shallow wells dug along the Shabelle River bed, which is dry due to drought in Somalia's Shabelle region, March 19, 2016. The cabinet ministers of the federal republic of Somalia have held on Thursday their weekly meeting in Mogadishu and discussed on the drought situation in parts of the country and its humanitarian consequences. Chaired by the acting PM and justice minister Abdullah Ahmed Jama (Ilka-Jir), the cabinet noted with deep concern the the prevailing situation in Somalia, with one of the worst ever drought in two decades. (Photo by Feisal Omar/Reuters)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

People take part in a sunset ceremony on the lower slopes of Glastonbury Tor as they celebrate Samhain at the Glastonbury Dragons Samhain Wild Hunt 2017 in Glastonbury on November 4, 2017 in Somerset, England. To celebrate Samhain, the Glastonbury Dragons, alongside Gwythyr Ap Greidal, the Summer King and the Winter King, (Photo by Matt Cardy/Getty Images)