Washington: Greenland may lose 4.5 per cent of its ice by the end of this century — contributing up to 13 inches of sea level rise — if worldwide greenhouse gas emissions remain on their current trajectory, a study has warned.
According to the research, the island may become ice-free by the year 3000.
“How Greenland will look in the future — in a couple of hundred years or in 1,000 years — whether there will be Greenland, or at least a Greenland similar to today, it’s up to us,” said Andy Aschwanden, a research associate professor at the University of Alaska in the US.
The research uses new data on the landscape under the ice today to make breakthroughs in modeling the future.
The findings show a wide range of scenarios for ice loss and sea level rise based on different projections for greenhouse gas concentrations and atmospheric conditions.
Currently, the planet is moving toward the high estimates of greenhouse gas concentrations.
Greenland’s ice sheet is huge, spanning over 660,000 square miles. Today, the ice sheet covers 81 per cent of Greenland and contains 8 per cent of Earth’s fresh water.
If greenhouse gas concentrations remain on the current path, the melting ice from Greenland alone could contribute as much as 24 feet to global sea level rise by the year 3000, which would put much of San Francisco, Los Angeles, New Orleans and other cities under water.
However, if greenhouse gas emissions are cut significantly, that picture changes. Instead, by 3000 Greenland may lose 8 to 25 per cent of ice and contribute up to approximately 6.5 feet of sea level rise.
Between 1991 and 2015, Greenland’s ice sheet has added about 0.02 inches per year to sea level, but that could rapidly increase.
Projections for both the end of the century and 2200 tell a similar story: There are a wide range of possibilities, including saving the ice sheet, but it all depends on greenhouse gas emissions.
The researchers ran 500 simulations for each of the three climate scenarios to create a picture of how Greenland’s ice would respond to different climate scenarios.
The model included parameters on ocean and atmospheric conditions as well as ice geometry, flow and thickness.
Simulating ice sheet behaviour is difficult because ice loss is led by the retreat of outlet glaciers. These glaciers, at the margins of ice sheets, drain the ice from the interior like rivers, often in troughs hidden under the ice itself.
The study is the first model to include these outlet glaciers. It found that their discharge could contribute as much as 45 per cent of the total mass of ice lost in Greenland by 2200.
PTI