The Aletsch Glacier is pictured at dusk in Fiesch, Switzerland, August 11, 2015. One of Europe's biggest glaciers, the Great Aletsch coils 23 km (14 miles) through the Swiss Alps – and yet this mighty river of ice could almost vanish in the lifetimes of people born today because of climate change. The glacier, 900 metres (2,950 feet) thick at one point, has retreated about 3 km (1.9 miles) since 1870 and that pace is quickening. (Photo by Denis Balibouse/Reuters)

Sonny Colbrelli of Italy celebrates winning the men's Paris Roubaix, a 258 kilometer (160.3 miles) one-day-race cycling race, at the velodrome in Roubaix, northern France, Sunday, October 3, 2021. (Photo by Vincent Kalut/Pool Photo via AP Photo)

A couple passes the sculpture “Transformer” by Chinese artist Bi Heng during snowfall in Kassel, central Germany, Tuesday March 12, 2013. Frankfurt airport closed, a quarter of flights out of Paris were canceled, Belgium suffered record traffic jams and high-speed trains were stuck in stations – all because of a sudden dump of oddly late snowfall on Western Europe. Less prepared for the kind of heavy snow that regularly hits northern and eastern neighbors, France, Britain and Belgium struggled Tuesday to keep moving amid the frosty, blustery conditions. (Photo by Uwe Zucchi/AP Photo/Dpa)

Close Encounter of the Insect Kind: “Check out the awesome face on this praying mantis. I can't get over the mouth, it's like something from a science fiction movie. Of all photographic styles macro is definitely my favorite. I am constantly amazed, in every photo that I take, by the intricate level of detail that exists on even the smallest of creatures. It's a stark reminder that a very complex and infinitely beautiful world exists just beyond our human-sized level of perception. Photo taken in Donnybrook, Queensland, Australia” – Andrew Young. (Photo by Andrew Young/National Geographic Photo Contest via The Atlantic)

The unromantic gypsies. Children boxing in a gypsy camp in Kent, England on July 1, 1951. Like all boys these gypsy lads like to try their hand at boxing. Encouraged by their friends they fight it out on Corke's Meadow. Few Romanies now live a life of wandering romance. Most are like the three hundred squatters of Corke's Meadow, Kent, which is part of a “gypsy problem” that involves about 100,000 today. Of those about 25,000 can be rightly called gypsies, the rest are Mumpers and Posh-rats and Hobos. Corke's Meadow has both kinds. “Picture Post” cameraman Bert Hardy photographs the Corke's Meadow gypsies in their encampment. (Photo by Hulton-Deutsch Collection/Corbis via Getty Images)

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)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

“The Pugs of Westeros” sees Roxy, Blue and Bono playing doggy versions of the main characters, including conniving King Joffrey. The pugs’ owners, Phillip Lauer (57) and his wife Sue (47), have been dressing their pugs up as characters from cinema and TV since they were puppies. They jumped at the chance of creating a picture series based on one of their favourite shows. Sue spent two weeks just creating the Iron Throne alone but it was well worth it. (Photo by Phillip Lauer)