Having released about 500 gigatons of carbon, were about halfway to the first tipping point.
” The first tipping point is not far from todays climate conditions, so were in threat of crossing it,” said Dennis Höning, an environment researcher at the Potsdam Institute for Climate Impact Research who led the research study. “Once we start moving, we will fall off this cliff and can not climb up back up.”
The study was released in AGUs journal Geophysical Research Letters, which publishes short-format, high-impact research study spanning the Earth and area sciences.
When Greenlands ice sheet melts, it loses elevation and is exposed to warmer air. The warmer air then increases melt further. Credit: NASA GSFC
The Greenland Ice Sheet is already melting; in between 2003 and 2016, it lost about 255 gigatons (billions of tons) of ice each year. Much of the melt to date has actually been in the southern part of the ice sheet. Air and water temperature level, ocean currents, rainfall, and other factors all figure out how quickly the ice sheet melts and where it loses ice.
The intricacy of how those factors affect each other, together with the long timescales scientists require to think about for melting an ice sheet of this size, make it hard to predict how the ice sheet will react to various environment and carbon emissions scenarios.
Previous research study identified international warming of in between 1 degree to 3 degrees Celsius (1.8 to 5.4 degrees Fahrenheit) as the threshold beyond which the Greenland Ice Sheet will melt irreversibly.
To more comprehensively model how the ice sheets action to climate might evolve in time, Hönings new research study for the first time used a complex design of the whole Earth system, which consists of all the crucial climate feedback processes, combined with a model of ice sheet behavior. They first used simulations with constant temperatures to discover balance states of the ice sheet, or points where ice loss equaled ice gain. They ran a set of 20,000-year-long simulations with carbon emissions ranging from 0 to 4000 gigatons of carbon.
From among those simulations, the researchers obtained the 1000-gigaton carbon tipping point for the melting of the southern portion of the ice sheet and the much more risky 2,500-gigaton carbon tipping point for the disappearance of nearly the whole ice sheet.
As the ice sheet melts, its surface area will be at ever-lower elevations, exposed to warmer air temperature levels. Even if climatic carbon dioxide were lowered to pre-industrial levels, it would not be enough to allow the ice sheet to grow back considerably.
” We can not continue carbon emissions at the same rate for a lot longer without running the risk of crossing the tipping points,” Höning stated. “Most of the ice sheet melting wont happen in the next decade, however it wont be too long prior to we will not be able to work versus it any longer.”
Reference: “Multistability and Transient Response of the Greenland Ice Sheet to Anthropogenic CO2 Emissions” by Dennis Höning, Matteo Willeit, Reinhard Calov, Volker Klemann, Meike Bagge and Andrey Ganopolski, 27 March 2023, Geophysical Research Letters.DOI: 10.1029/ 2022GL101827.
If it melts totally, global sea level would increase about 7 meters (23 feet), however scientists arent sure how quickly the ice sheet could melt. The Greenland Ice Sheet is already melting; between 2003 and 2016, it lost about 255 gigatons (billions of tons) of ice each year. Air and water temperature level, ocean currents, precipitation, and other aspects all figure out how quickly the ice sheet melts and where it loses ice.
To more thoroughly model how the ice sheets action to climate could progress over time, Hönings brand-new study for the first time utilized a complicated design of the entire Earth system, which consists of all the key environment feedback processes, paired with a model of ice sheet behavior. They initially utilized simulations with consistent temperature levels to discover balance states of the ice sheet, or points where ice loss equated to ice gain.
Much of the southern Greenland Ice Sheet, shown here, will melt irreversibly if we produce about 1000 gigatons of carbon, according to designs in a new Geophysical Research Letters research study. Credit: NASA GSFC
Much of the enormous ice sheet will melt irreversibly once we discharge about 1000 gigatons of carbon. Weve released 500 gigatons up until now.
The Greenland Ice Sheet covers 1.7 million square kilometers (660,200 square miles) in the Arctic. If it melts completely, worldwide water level would rise about 7 meters (23 feet), but scientists arent sure how quickly the ice sheet might melt. Designing tipping points, which are crucial thresholds where a system habits irreversibly alters, assists researchers discover when that melt might happen.
Based in part on carbon emissions, a new study using simulations identified two tipping points for the Greenland Ice Sheet: launching 1000 gigatons of carbon into the atmosphere will cause the southern portion of the ice sheet to melt; about 2500 gigatons of carbon means permanent loss of nearly the whole ice sheet.