"That's how climate change works. Today's outliers become tomorrow's averages." William Colgan, at the Geological Survey of Denmark and Greenland.
New research indicates that an absolute sea level rise of over ten inches is now inevitable, no matter what we do to prevent it.
That ten inches of meltwater may not sound like much, but it is twice the IPCC forecast amount and does not include the dangers from storm surges, thermal expansion, and high tides. This is the best-case scenario of Greenland sea level contributions, warn scientists.
The world's low-lying coastlines are now undeniably at risk. The study does not include West or East Antarctica contributions or glaciated mountain ranges.
Seth Borenstein writes in Phys.org
That's because of something that could be called zombie ice. That's doomed ice that, while still attached to thicker areas of ice, is no longer getting replenished by parent glaciers now receiving less snow. Without replenishment, the doomed ice is melting from climate change and will inevitably raise seas, said study co-author William Colgan, a glaciologist at the Geological Survey of Denmark and Greenland.
"It's dead ice. It's just going to melt and disappear from the ice sheet," Colgan said in an interview. "This ice has been consigned to the ocean, regardless of what climate (emissions) scenario we take now."
Study lead author Jason Box, a glaciologist at the Greenland survey, said it is "more like one foot in the grave."
The unavoidable ten inches in the study is more than twice as much sea level rise as scientists had previously expected from the melting of Greenland's ice sheet. The study in the journal Nature Climate Change said it could reach as much as 30 inches (78 centimeters). By contrast, last year's Intergovernmental Panel on Climate Change report projected a range of 2 to 5 inches (6 to 13 centimeters) for likely sea level rise from Greenland ice melt by the year 2100.
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Colgan said this is actually all a best case scenario. The year 2012 (and to a different degree 2019 ) was a huge melt year, when the equilibrium between adding and subtracting ice was most out of balance. If Earth starts to undergo more years like 2012, Greenland melt could trigger 30 inches (78 centimeters) of sea level rise, he said. Those two years seem extreme now, but years that look normal now would have been extreme 50 years ago, he said.
"That's how climate change works," Colgan said. "Today's outliers become tomorrow's averages."
Of course, we have done little to nothing to prepare ourselves for disaster.