A hiker admires the view as Mt. Etna, Europe's largest active volcano, erupts in the background, in the Bove Valley of Etna Park, on the eastern slope of Mt. Etna, in Sicily, southern Italy, Sunday, July 4, 2021. Since Feb. 16, 2021, Mt. Etna has begun a series of eruptive episodes. (Photo by Salvatore Allegra/AP Photo)

Anthony Joshua punches Kubrat Pulev during the IBF, WBA, WBO and IBO World Heayweight Title fight between Anthony Joshua and Kubrat Pulev at The SSE Arena, Wembley on December 12, 2020 in London, England. A limited number of fans (1000) are welcomed back to sporting venues to watch elite sport across England. This was following easing of restrictions on spectators in tiers one and two areas only. (Photo by Andrew Couldridge – Pool/Getty Images)

People drink in the street in the Soho area of London, on April 12, 2021 as coronavirus restrictions are eased across the country in step two of the government's roadmap out of England's third national lockdown. Britons on Monday toasted a significant easing of coronavirus restrictions, with early morning pints – and much-needed haircuts – as the country took a tentative step towards the resumption of normal life. Businesses including non-essential retail, gyms, salons and outdoor hospitality were all able to open for the first time in months in the second step of the government's roadmap out of lockdown. (Photo by Tolga Akmen/AFP Photo)

American stand-up comedian and actress Whitney Cummings fools around with photographers after she, Griffin Johnson, and Josh Richards have dinner together at Craig's in West Hollywood, CA. on April 6, 2021. (Photo by Backgrid USA)

A passer-by takes a selfie with an extra newspaper reporting on President-elect Joe Biden's win in the U.S. presidential election, in Tokyo Sunday, November 8, 2020. The headline reads: “Mr. Biden Assured to win”. (Photo by Eugene Hoshiko/AP Photo)

A woman poses for a picture near an ice hole as a man takes a dip during celebrations of the Orthodox Christian feast of Epiphany in the settlement of Ivanovskoye in the Moscow region, Russia on January 19, 2022. (Photo by Maxim Shemetov/Reuters)

This photo taken on April 4, 2021 shows migratory birds flying over a wetland near the Yalu River in Dandong, in China's northeastern Liaoning province. (Photo by AFP Photo/China Stringer Network)

The Greenland ice sheet is a vast body of ice covering 660,235 sq miles, roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after the Antarctic Ice Sheet. Some scientists predict that climate change may be near a "tipping point" where the entire ice sheet will melt in about 2000 years. If the entire 2,850,000 cubic kilometres (683,751 cu mi) of ice were to melt, it would lead to a global sea level rise of 7.2 m (23.6 ft).