Zombie ice threatens global sea level rise, 10-inch jump unavoidable

Zombie ice threatens global sea level rise, 10-inch jump unavoidable

Even if the whole world stopped burning fossil fuels today, the Greenland Ice Sheet would still lose about 110 quadrillion tonnes of ice.


HIGHLIGHTS

* The latest forecast is nearly twice as much as the previous predictions

* Researchers calculated the average snow line needed to bring the ice sheet back into balance.

* Sea level rise is being attributed to something called zombie ice


As climate change continues to wreak havoc across the world with extreme droughts in China to heavy floods in parts of India and Pakistan, another major concern is brewing in an isolated corner of the planet. Greenland is on course to raise global sea levels by at least 27 centimeters or 10.6 inches.

The latest forecast is nearly twice as much as the previous predictions and it is being attributed to something called zombie ice. This dead ice, while still attached to thicker areas of ice, is no longer getting replenished by parent glaciers now receiving less snow and, without any replenishment, is melting from climate change unchecked.

Researchers from the Geological Survey of Denmark and Greenland have noted that even if the whole world stopped burning fossil fuels today, the Greenland Ice Sheet would still lose about 110 quadrillion tonnes of ice leading to an average global sea level rise of at least 27 centimeters.

"It is a very conservative rock-bottom minimum. Realistically, we will see this figure more than double within this century. In the foreseeable scenario that global warming will only continue, the contribution of the Greenland Ice Sheet to sea level rise will only continue increasing," Professor Jason Box, who led the study, said in a statement.

The study published in the journal Nature Climate Change states that the sea level could rise as much as 30 centimeters.

Scientists looked at the climate in the Arctic from 2000 to 2019 and the imbalance it has created in the Greenland Ice Sheet and calculated the shape of the ice is set in motion to correct this imbalance.

"When we take the extreme melt year 2012 and take it as a hypothetical average constant climate later this century, the committed mass loss from the Greenland Ice Sheet more than doubles to 78 cm," Professor Jason Box added.

In perfect equilibrium, snowfall in the mountains in Greenland flows down and recharges and thickens the sides of glaciers, balancing out what’s melting on the edges. But in the last few decades, there’s less replenishment and more melting, creating imbalance. Study authors looked at the ratio of what’s being added to what’s being lost and calculated that 3.3% of Greenland’s total ice volume will melt no matter what happens with the world cutting carbon pollution.

Using a rigorous glaciological theory abiding the physics of ice flow based on measurements from satellites and other observations, they calculated the average snow line needed to bring the ice sheet back into balance.

This is the first time scientists calculated a minimum ice loss — and accompanying sea level rise — for Greenland, one of Earth’s two massive ice sheets that are slowly shrinking because of climate change from burning coal, oil, and natural gas.

Zombie ice threatens global sea level rise, 10-inch jump unavoidable