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)

Syrian girls carry bags with bread as people queue up outisde a bakery in a rebel held neighbourhood in the northern city of Aleppo on July 12, 2016. Since mid-2012, Aleppo has been roughly divided between government control in the west and rebel control in the east, and has suffered enormous destruction in the war that has killed more than 280,000 people nationwide. Last week, a government advance brought regime troops within firing range of the Castello Road, the only remaining supply route into the opposition-held east, effectively severing rebel neighbourhoods from the outside world. With their route to the outside world cut, there is no new flour coming to the city's bakeries, and fuel to light their ovens is also now hard to find. (Photo by Karam Al-Masri/AFP Photo)

In Jukkasjärvi, a village a few miles east of Kiruna, the proprietors of one hotel begin planning for a winter ice festival in March. That’s when they begin collecting some 5,000 tons of ice from the River Torne in order to prepare the Icehotel, the world’s coolest place to stay. Options for overnight stay include snow rooms, ice rooms, art suites, and the Northern Lights room, all of which range from about $300 to $900 per night. But the deluxe suite’s the only way to go. These rooms come with a critical amenity: heated ensuite bathrooms and saunas. Here: A man walks into a room in the Ice hotel in Jukkasjarvi, Sweden, December 16, 2015. (Photo by Ints Kalnins/Reuters)

Some of the best entries so far in the 2016 Insight Astronomy Photographer of the Year competition. There are two weeks left to enter, and the winners will be announced in September. Here: Aurora over Laksvatn Fjord, Laksvatn, Norway. The aurora borealis dances in the skies over the town of Laksvatn, with the Milky Way to the left. The image is a single shot with no compositing, only post-processing to bring out the aurora, and some colour corrections. The photographer Matt Walford said: “I love the way the northern lights look like they are just wistfully dancing over the fjord, framed by the mountains on either side”. (Photo by Matt Walford/National Maritime Museum)

People light fireworks to celebrate Diwali, the Hindu festival of lights, in New Delhi, India on November 12, 2023. (Photo by Anushree Fadnavis/Reuters)

A visitor is reflected in a light installation at Mulberry Lights on Regent Street in London, UK on November 16, 2018. Visitors have fun taking selfies and posing with the colourful light installations. Mulberry Lights is a series of illuminating interactive experiences that celebrate how light, colour, shapes and people come together to create a modern British Christmas. (Photo by Imageplotter/Rex Features/Shutterstock)

Locals light firecrackers on the occasion of Diwali, the Hindu festival of lights, in Chennai, India on November 12, 2023. (Photo by Idrees Mohammed/EPA/EFE)

A Hindu woman hold clay-lamp during a ceremony to celebrate Diwali, the festival of lights, at Krishna temple in Lahore, Pakistan, Sunday, November 12, 2023. The Hindu festival of lights, Diwali celebrates the spiritual victory of light over darkness. (Photo by K.M. Chaudary/AP Photo)