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).

A boat commutes across the Mekong river in Phnom Penh on August 8, 2014. The Mekong is the world's twelth longest river running from the Tibetan Plateau through China's Yunnan province, Myanmar, Laos, Thailand, Cambodia and Vietnam. (Photo by Tang Chhin Sothy/AFP Photo)

A German rifleman beside the corpse of a French soldier in a trench at Fort Vaux, France, 1916. (Photo by Hulton Archive/Getty Images)

Chrissy Teigen and daughter Luna Stephens seen on the streets of Manhattan on June 24, 2019 in New York City. (Photo by James Devaney/GC Images)

American singer Melissa Viviane Jefferson, known professionally as Lizzo performs at O2 Academy Brixton on November 06, 2019 in London, England. (Photo by Chiaki Nozu/WireImage)

English journalist and newsreader Lucy Watson attends the “Charlie's Angels” UK Premiere at The Curzon Mayfair on November 20, 2019 in London, England. (Photo by Jeff Spicer/Getty Images)

The pedestrian zone on the banks of the “Parco della Pace” at Lake Maggiore is flooded due to flooding, on Thursday, October 24, 2019 in Locarno, Switzerland. (Photo by Samuel Golay/Ti-Press/Keystoen)

Waves hit the seawall during heavy seas and high winds in Dawlish in south west Britain, February 2, 2017. (Photo by Toby Melville/Reuters)