The already hot situation on Earth is being blamed for the current melting of ice, and rising sea levels. However, according to the Ice Sheet Model Intercomparison Project (ISMIP6), under the leadership of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, further melting is to be considered.
It saw more than 60 experts in ice, ocean, and atmospheric research – from three dozen different international institutions around the world – to find out what happens when the ice sheets of Greenland and Antarctica melt. The results of two studies, published in the journal The Cryosphere, make for ominous reading.
By the year 2100, he concluded, and if greenhouse emissions are reduced from their current levels, the combined ice sheet may melt causing a rise in global sea level by more than 15 inches. Those ice sheets are believed to increase about one-third of the total global sea level. Earlier studies have suggested that even if we make changes now, sea level will rise by about a quarter inch by 2100.
“One of the biggest uncertainties is how much sea level will rise in the future, how much the ice sheets will contribute,” Sophie Nicky, now at the University of Buffalo, and formerly at NASA Goddard, and project leader of the study, said today. “And how much the ice sheets contribute depends on what the climate will do.”
The challenge is that the ice sheets at the north and south poles have a double effect due to shrinking, and in this process a large amount of water is released. On the one hand, the air temperature is rising, which melts the surface level ice. At the same time, the sea temperature is also increasing, causing the glaciers to shrink and retreat. A study in August predicted that there could be a risk of unexpectedly precarious ice shelves shearing away in the Antarctic, dramatically speeding up the process at which the ice melts.
This latest study investigated two possibilities. On the positive side, the team created a low emissions scenario, where carbon emissions dramatically decreased. The global sea level is still seen to rise by about 1.3 inches.
The second model took a more pessimistic approach, where emissions were greatly reduced in the way of attempts to test their production. There, he concluded that melting ice sheets could increase about 3.5 inches in the already growing oceans.
Further complicating borrowing is the fact that change and melt-rates are not consistent across all regions. Some areas are more susceptible to differences in warm ocean and currents: the Amundsen Sea region in West Antarctica, and the Wilkes Land in East Antarctica, for example, are cited as being most vulnerable to changes in simulations.
“With these new results, we can focus our efforts in the right direction and find out what needs to be done to improve projections,” an ice scientist at NASA’s Jet Propulsion Laboratory in Southern California, And Helene Ceaurosi Ice Sheet Modeling, Leading on the Antarctic, explains.