A recent scientific analysis reveals that Earth's glaciers are in critical condition, with nearly 40% of their ice mass effectively beyond saving – even if global temperatures were to stabilise immediately.

The researchers project that glaciers are set to shrink by 39% relative to their 2020 size, a decline that is now locked in and expected to contribute roughly 113 mm to sea-level rise worldwide.

If current international climate strategies remain unchanged, that projected loss could grow to 76%, a scenario that would push global temperatures above the 1.5°C limit targeted in global agreements, according to new research featured in the journal Science.

This steep increase in melting could have severe consequences for nations dependent on glacier runoff for agriculture, hydropower, and clean water supplies.

As glaciologist James Kirkham of the International Cryosphere Climate Initiative told CNN, the contrast between losing 39% versus 76% of glacier ice “is the difference between being able to adapt to the loss of the glacier and not.”

Despite the grim outlook, co-author Lilian Schuster of the University of Innsbruck emphasised that the study offers a reason to remain hopeful. “With the study, we want to show that with every tenth of a degree less of global warming, we can preserve glacier ice,” she said in comments to CNN.

The 2015 Paris Agreement saw nearly 200 countries commit to curbing temperature rise to well below 2°C above pre-industrial levels, aiming ideally for a cap of 1.5°C. Each nation was tasked with formulating its own strategy to meet these climate goals.

However, recent projections suggest that the planet could see warming as high as 2.9°C by the end of the century. The study notes that each additional 0.1°C between 1.5°C and 3°C would lead to another 2% of glacier mass loss.

“We’re not activists, this is science talking,” Harry Zekollari, who co-led the research and is affiliated with Vrije Universiteit Brussel and ETH Zürich, told CNN. “Sometimes, the remarks we get is like ‘you’re alarmist and making people scared.’ I say, ‘I’m trying to give out what our computer numbers give us.’”

The glaciologist Kirkham, who presented the findings at a recent United Nations event, called the work a “landmark” and added that it stands out as “one of the most important pieces of glacier projection work that’s been done this decade.” He noted that past glacier modelling typically stopped at the year 2100, though glaciers take far longer to adjust to temperature shifts – often concealing the full impact of warming.

To address this time lag, the study used eight previously developed glacier models and ran them over multi-century timescales to estimate long-term changes in glacial volume. This approach yielded a broad set of outcomes, with estimates of eventual loss ranging from 15% to 55%, depending on the assumptions used. The 39% figure represents the median.

While this range is considerable, Guðfinna Aðalgeirsdóttir of the University of Iceland, who was not involved in the project, noted the consistency among the results: “All the models are showing the same thing, that with increased warming, the more mass of glaciers we lose,” she said to CNN. “The message is very clear.”

Zekollari acknowledged that the differences between model outputs highlight the need for more in-depth comparisons: “There’s still a lot to be done when it comes to comparing the different models.”

The study also highlights that some glacier regions face greater risks than others, depending on their local climate vulnerabilities. Areas identified as particularly susceptible include Western and Northeastern Canada, parts of the US, Scandinavia and the Russian Arctic.