The predicted sea rise of 27 cm is more than twice what scientists had previously expected from the melting Greenland ice sheet.
Greenland’s fast-melting ice sheet will cause massive sea-level rise this century with potentially dire consequences if temperatures continue to rise, according to a study published Monday.
Melting “zombie” ice cream from the huge Greenlandic Ice Sheet eventually alone will raise the world’s sea level by at least 27 centimeters (10 inches). “Zombie”, or doomed ice, still clings to thicker areas of the blade, but is no longer fed by larger glaciers.
The study in the journal Nature Climate Change Sea level rise could reach as much as 78 cm (30 in) — enough to inundate vast low-lying coastlines and accelerate flooding and storm surges.
This should serve “as an ominous forecast for Greenland’s trajectory through a 21st century of warming,” the authors said.
In contrast, last year’s report by the Intergovernmental Panel on Climate Change (IPCC) predicted a range of 6-13 cm (2-5 inches) for the likely sea level rise from the melting of the Greenland ice by the year 2100.
Glaciologists found that regardless of any future pollution from fossil fuels, warming thus far will cause the Greenland ice sheet to lose 3.3 percent of its volume, raising sea levels by 27.4 cm.
The study’s lead author, Jason Box, a glaciologist with the Greenland survey, said it’s “like a foot in the grave.”
Co-author William Colgan, a glaciologist with the Geological Survey of Denmark and Greenland, said: “This ice has been sent to the ocean regardless of the climate. [emissions] scenario we are taking now.”
‘radically different’ methodology
The theory researchers used was initially developed to explain changes in Alpine glaciers, Box said.
This is true when more snow accumulates on a glacier, causing lower areas to expand. In this case, the reduced snow in lower parts of the glacier is shrinking as it rebalances, he said.
Box said the methods his team used were “radically different” than computer modeling, but could complement this work to predict the effects of sea level rise in the coming decades.
He said that while climate change brought more immediate threats, such as food security, the accelerating rate of sea level rise will be a huge challenge.
“It’s kind of like decades into the future when it’s just going to get on the agenda because it’s going to start displacing people more and more,” Box said.
This is the first time scientists have calculated minimal ice loss — and associated sea level rise — for Greenland, one of two giant ice sheets on Earth that are slowly shrinking due to climate change from burning coal, oil and natural gas.
The world has warmed an average of nearly 1.2 degrees Celsius since pre-industrial times, unleashing a catalog of effects from heat waves to more intense storms.
In the Paris climate agreement, countries agreed to limit warming to 2 degrees Celsius.
But in this year’s report on climate impacts, the IPCC said that even if warming stabilizes at 2C to 2.5C (35.6F to 36.5F), “coastlines will continue to reshape over millennia, impacting at least 25 megacities and drowning.” low-lying areas”, where up to 1.3 billion people lived in 2010.
Colgan said his research team doesn’t know how long it will take for all the doomed ice to melt, but an educated guess would likely be by the end of this century, or at least by 2150.
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