Rising sea levels in certain regions of the world could reach alarming rates of 8 to 12 inches per decade, posing significant challenges for coastal communities to adapt, according to a recent study released by an international team of polar ice and sea level experts.
The findings highlight that aiming to limit global warming to 2.7° Fahrenheit (1.5° Celsius) above pre-industrial temperatures, as outlined in the Paris Climate Agreement, might not be sufficient to avert severe melting of Earth’s polar ice sheets.
Chris Stokes, a geographer and glacier expert from Durham University, who co-authored the study, emphasized that a more appropriate target for maintaining a stable climate could be closer to 1.8° Fahrenheit.
Stokes pointed out that recent high-profile studies have increasingly advocated for stricter long-term climate goals.
He noted, “There have been a couple of quite high-profile papers recently, including a synthesis in Nature looking at safe planetary boundaries. They made the argument that 1° Celsius is a better goal.”
The conversation surrounding these climate targets is not new; earlier studies, dating back to before the first Intergovernmental Panel on Climate Change report in 1990, raised alarms about the risks associated with exceeding 1° C of warming.
Stokes remarked on the continuity of these concerns over the decades, highlighting the scientific consensus that caps at around 350 parts per million of carbon dioxide in the atmosphere are vital for avoiding drastic consequences.
At present, Earth’s global temperature has surpassed the 1.5° C target almost every month for two consecutive years, with atmospheric carbon dioxide concentrations reaching 430 ppm—a 50 percent increase from pre-industrial levels.
Despite missing interim climate goals, revising targets remains crucial, as the Paris Agreement includes mechanisms for review, according to Stokes.
“Even if the global temperature overshoots the 1.5° mark, it’s important to know for the long term how much it would have to be lowered to return to a safe climate range,” he added.
The researchers specifically assessed how melting polar ice masses contribute to sea level rise by analyzing evidence from historical warm periods and by measuring current ice loss under present warming conditions.
Projected estimates indicate a rapid surge in sea level rise that could double in rate from the current few millimeters per year, overwhelming adaptation efforts in many U.S. coastal communities, as noted by co-author Andrea Dutton, a geoscientist at the University of Wisconsin-Madison.
Dutton stated that communities currently preparing for future sea level rise are focused on existing conditions rather than anticipating potentially escalating scenarios.
Historical data from the mid-Pliocene warm period reveal that the last time atmospheric carbon dioxide levels were similar to today’s, sea levels rose 35 to 70 feet over thousands of years—a much slower process than what is currently unfolding.
The current rate of warming is unprecedented in geological history, making the response of ice sheets to rapid temperature increases uncertain, but evidence suggests Arctic changes are occurring quicker than scientists had predicted.
Significantly, Dutton noted that budget cuts to federal science agencies and staffing also threaten the nation’s capability to respond to rising sea levels, compounding the risks faced by coastal communities.
She mentioned that reduced funding for science research, the retraction of promised federal support through the Inflation Reduction Act, and the abandonment of the National Climate Assessment endanger efforts to project future sea level rise.
“The ice sheets won’t care what different political parties ‘believe’ about climate change,” Dutton stated.
“Like it or not, they are simply at the mercy of rising temperatures.”
Research shows that the mass of ice lost from polar ice sheets has quadrupled since the 1990s, with current losses estimated at around 370 billion metric tons of ice per year.
Co-author Jonathan Bamber, a physicist at the University of Bristol specializing in polar research, explained that advancements in technology over the last few decades have highlighted the rapid and significant changes in ice sheets, surpassing previous models’ projections.
He pointed out that earlier climate models predicted approximately half as much melting as is now being observed, suggesting that the safe atmospheric carbon dioxide level for humanity is around 350 ppm, consistent with a warming of about 1° C.
Bamber stated, “I think we’ve known for a long time that we’re interfering with the climate system in a very dangerous way. And one of the points of our paper is to demonstrate that one part of the climate system, the ice sheets, are showing some very disturbing signals right now.”
Some of the most threatened regions, such as Belize City, may be well outside the areas directly experiencing melting ice sheets.
The city, housing approximately 65,000 residents, could lose 500 square miles of land with just 3 feet of sea level rise.
In low-lying tropical regions near the equator, sea level is increasing three times faster than the global average, due to warmer water expansion and reduced gravitational pull from melting ice sheets.
Bamber warned, “It’s bad news for places like Bangladesh, India, Vietnam, and the Nile Delta.”
The implications of reaching a 1.5° C temperature increase are dire, according to Ambassador Carlos Fuller, a seasoned climate negotiator from Belize, reiterating the urgency of the study’s findings.
Belize has already relocated its capital inland, but its largest city remains vulnerable to flooding even at just 1 meter of sea level rise.
Fuller asserted, “Findings such as these only sharpen the need to remain within the 1.5° Paris Agreement limit, or as close as possible, so we can return to lower temperatures and protect our coastal cities.”
While the research primarily focuses on ice sheets, Stokes mentioned that other Earth systems are nearing irreversible tipping points that directly impact human civilization, including freshwater systems and ocean acidification.
Stokes concluded by stating, “I think somebody used the analogy that it’s like you’re wandering around in a dark room. You know there’s a monster there, but you don’t know when you’re going to encounter it. It’s a little bit like that with these tipping points. We don’t know exactly where they are. We may have even crossed them, and we do know that we will hit them if we keep warming.”
image source from：https://arstechnica.com/science/2025/05/paris-agreement-target-wont-protect-polar-ice-sheets-scientists-warn/
