New research indicates that the ice sheets in Greenland and Antarctica are melting at an alarming rate, and it may be impossible to halt this trend. This could result in several feet of sea-level rise, potentially displacing millions from coastal regions. Even if global warming is limited to the 1.5-degree Celsius threshold that world leaders have aimed for, scientists warn that melting may persist unchecked.
Published on Tuesday in Nature, this study integrates satellite observations, climate modeling, and historical data including ice cores and deep-sea sediments, alongside octopus DNA, to identify the “safe limits” for warming that could allow Earth’s largest ice sheet to survive.
The findings suggest that even the current temperature rise of about 1.2°C can trigger irreversible ice sheet retreats and that conditions could worsen as emissions continue, predicting a potential increase of up to 2.9 degrees by 2100.
The ice sheets in Greenland and Antarctica hold enough ice to raise global sea levels by around 213 feet. While such predictions are extreme, the research indicates there’s a significant risk of multi-foot sea-level rises over time. Since the 1990s, ice loss from these regions has quadrupled, with around 370 billion tonnes melting annually—making it the most significant contributor to rising oceans. Alarmingly, the rate of sea-level rise has doubled in the last three decades.
“Sea level rise never slows down to 1.5. In fact, we see very rapid acceleration,” stated Chris Stokes, a glaciologist at Durham University and one of the study’s authors. CNN.
Currently, about 230 million people live less than 1 meter (approximately 3.2 feet) above sea level. The study warns that even minor amounts of ice melt could reshape coastlines, force hundreds of millions to relocate, and cause damage beyond the capacity of many areas to manage.
By the end of this century, sea levels could rise by roughly 0.4 inches a year, culminating in an increase of approximately 40 inches over the century.
Experts find it challenging to pinpoint when an ice sheet might reach a critical tipping point, but the risks seem to be more imminent than previously thought. Earlier studies indicated that significant collapse of Greenland’s ice sheets would only start after a warming of about 3 degrees; now, it seems to be possible at just 1.5°C.
To avert this outcome, global warming needs to be capped at 1 degree C, necessitating a swift decline in fossil fuel usage. However, experts deem this goal unlikely, given the ongoing reliance on oil, coal, and gas by major countries like the US.
“We rarely see anything here that gives us hope,” Stokes noted. “The absolute best-case scenario is a gradual and stable rise in sea levels.”
Nonetheless, researchers emphasize the importance of striving to stay as close as possible to the 1.5°C target. “Limiting warming to 1.5 is a major accomplishment. That should certainly be our aim, but the focus shouldn’t just be about stopping sea-level rise and ice melting,” Stokes concluded.
