We are halfway to the tipping point for the melting of the Greenland Ice Sheet

An aerial view of meltwater lakes that formed at the front of Russell Glacier, part of the Greenland Ice Sheet in Kangerlussuaq, Greenland, on August 16, 2022. Fronted by a wall of ice up to 60 meters high, advancing 25 meters (82 feet) annually, it is located on It is 25 km (16 mi) east of Kangerlussuaq in the municipality of Qigata in western Greenland and is included in the UNESCO World Heritage Site Aasivissuit-Nipisat.

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New research published this week in the journal Geophysical Research Letters finds that carbon emissions are halfway to a tipping point, beyond which a 6-foot sea-level rise from the melting of the Greenland ice sheet will be unstoppable.

“Once we emit more than 1,000 gigatonnes of carbon in total, we will not be able to stop the southern part of the Greenland Ice Sheet from completely melting in the long run, even if we completely stop emitting carbon after that. This melting would cause sea levels to rise by about 1.8m” Dennis Honingclimatologist at Potsdam Institute for Climate Impact Research Who is the lead author of the study, he told CNBC. (1.8 meters is 5.9 feet).

“Although this melting will take hundreds of years, future generations will not be able to stop it,” Hueng said.

The more Earth passes the first tipping point of 1,000 gigatonnes of carbon emissions, the faster the Greenland ice sheet will melt.

And now, we’re now at nearly 500 gigatonnes of carbon emissions emitted.

“Coastal areas are definitely going to be hit the hardest by this, especially in poor countries that don’t have modern coastal management,” Honing told CNBC.

Höning said the scientists found in Previous studies that the Greenland Ice Sheet could completely melt with a global warming of somewhere between 1 and 3 degrees Celsius (1.8 degrees to 5.4 degrees Fahrenheit).

But Hueng told CNBC that the methodologies of previous studies were less accurate because the assumptions made in those models were overly simplistic and therefore unrealistic.

“While exploring temperature-related tipping points is useful for understanding system stability, it is cumulative real-world carbon emissions that determine whether or not a tipping point is passed,” Höning told CNBC. “This is why we examined the links between cumulative carbon emissions and Greenland ice sheet inversion with a fully coupled Earth system model, which includes all relevant feedback processes, for the first time.”

Honing used a file CLIMBER-X computer system who represents the Earth’s evolution over long periods of time and measures it all in his paper titled: Plural susceptibility and transient response of the Greenland ice sheet to anthropogenic carbon dioxide emissions.

Measuring the melting of the Greenland ice sheet is difficult because it takes a long time to melt, and it doesn’t happen at a steady pace.

“Once a critical threshold is crossed, the system’s behavior changes qualitatively and approaches an entirely new equilibrium. This is due to self-reinforcing feedback mechanisms: When the ice sheet melts, its surface is exposed to warmer air temperatures at lower altitudes and melting is inevitable,” Huing told CNN. NBC.

It’s most accurate to measure total cumulative carbon emissions, Höning said, which are those released since 1850.

He added that if total carbon emissions remain below the 1,000 Gt carbon emission threshold, melting of the Greenland ice sheet will contribute “only” tens of centimeters to the overall sea level rise.

The second tipping point noted in the research will occur once 2,500 gigatonnes of carbon emissions are released into the atmosphere, at which point the entire Greenland ice sheet will melt and sea levels will rise by 6.9 meters, or 22.6 feet.

“It will take time for complete melting, hundreds or even thousands of years, especially if we get a little bit over the threshold,” Hueng said. “Although the concentration of carbon dioxide in the atmosphere will decrease over these long time scales, it will not decrease rapidly enough to stop the melting of the ice sheet.”

Theoretically, a synthetic carbon dioxide removal technology could pull enough carbon out of the atmosphere quickly enough after one of these tipping points is reached to recover the inevitable melt. But it is not a case study worth pursuing because the technology to remove this volume of emissions from the atmosphere does not exist at the moment.

“We’re not even close to the point where decarbonization is effective,” Hueng told CNBC. “Avoiding carbon emissions anyway is much cheaper than the energy required to capture that carbon again.”