Rising sea levels and the collapse of the “Doomsday Glacier” will rewrite the map of the world according to leading scientists.
Studies by the world’s leading climate scientists show that within 30 years rising sea levels will impact 800 million worldwide, creating a global catastrophe.
A new study published yesterday has estimated the unprecedented consequences of uncontrolled greenhouse gas (GHG) emissions is likely to see Greenland and Antarctica’s ice sheets together contribute more than 15 inches (38 centimetres) of global sea level rise by 2100.
At least 60 scientists studied the impact of melting ice sheets on global sea-level rise and arrived at the estimates, publishing results in journal The Cryosphere.
The study, by the Ice Sheet Model Intercomparison Project (ISMIP6) led by NASA’s Goddard Space Flight Centre said in the case of high GHG emissions, the Greenland ice sheet would lead to an additional global sea-level rise of about 3.5 inches (9 cm) by 2100. In the lower emissions scenario, the loss from the ice sheet would raise global sea-level by about 1.3 inches (3 cm).
What has raised concerns for both the scientific and risk communities is the estimated amount is much greater than what was projected to be lost from ice sheet melting between pre-industrial times and now.
Ice loss from the Antarctic ice sheet, however, was more difficult to predict, with results pointing to a range of possibilities.
In the west, warm ocean currents erode the bottom of large floating ice shelves, causing loss; while the vast East Antarctic ice sheet can gain mass, as warmer temperatures cause increased snowfall, according to the study.
The results were varied: There were possibilities of ice sheet change that decreased sea level by 3.1 in (7.8 cm), to increasing it by 12 in (30 cm) by 2100.
The greatest loss was projected in West Antarctica, contributing up to 7.1 inches (18 cm) of sea level rise by 2100 in the warmest conditions, according to regional projections.
The results were in line with projections of the Intergovernmental Panel on Climate Change’s (IPCC) 2019 Special Report on Oceans and the Cryosphere. It had projected that Greenland would contribute 3.1 to 10.6 inches (8 to 27 cm) to global sea-level rise between 2000-2100 and Antarctica could contribute 1.2 to 11 inches (3 to 28 cm).
Hélène Seroussi, who led the Antarctic ice sheet modelling in the ISMIP6 effort explained: “The Amundsen Sea region in West Antarctica and Wilkes Land in East Antarctica are the two regions most sensitive to warming ocean temperatures and changing currents, and will continue to lose large amounts of ice.”
The study came as new research on the Thwaites glacier, dubbed the “Doomsday Glacier” found it was melting at a faster rate then predictions had allowed for with the potential for catastrophic impacts in the next three decades. If the worst case scenario is realised it will melt with the next 200 years.
The report warned that rising sea levels have the potential to affect up to 800 million worldwide by the year 2050, with the power supply of 470 million threatened and high temperatures affecting 1.6 billion people. The threat of the doomsday glacier in Antarctica and sea level rise are just the beginning of a worldwide catastrophe.
Thwaites is a glacier in west Antarctica which is roughly the size of Britain. Scientists gave it the nickname because it is currently melting at a rapid rate, losing approximately 2,625 feet or one-half mile of ice each year.
Scientists say once Thwaites melts, its function as the buffer between other glaciers and the warming ocean will stop, triggering the collapse of nearby ice masses along with it. This will result in a rising of sea levels by almost 10 feet, which will permanently submerge many coastal cities such as parts of Miami, the Netherlands and New York,
New York University atmospheric science professor David Holland says that it will be a massive change, which will rewrite the coastline.
The study published in PNAS showed how sections of the Thwaites and Pine Island Glacier have faster melting rates than was thought in the past. These two glaciers melting has already increased sea levels worldwide by approximately five percent.
Thwaites is not the only problem. The ice sheet of the Antarctic also currently melts six times more rapidly than it did during the 1980s. It contributes 252 billion tons of water per year, compared to 40 billion tons yearly four decades ago.
According to University of Colorado senior scientist Ted Scambos, the satellites show that the Thwaites is being melted apart. The new study shows that this melting is due partly to the breaking up of the natural buffers sustaining Pine Glacier and Thwaites. The shear margins on Thwaites and Pine Island are losing integrity and are breaking.
The Pine Island Glacier has lost ice as large as the city of Los Angeles within the past six years. Lead author and satellite expert Stef Lhermitte says this ice shelf is starting to disappear.