Scientists warn that glaciers and ice sheets could reach critical tipping points even if global warming stays below 1.5°C.

 

KATHMANDU, JUNE 19 — Scientists told UN climate negotiators in Bonn that Earth's ice sheets and mountain glaciers could reach dangerous tipping points even if the temperature rise stays below 1.5°C. Experts who wrote two important reports—one on ice sheets and another on glaciers—are urging governments to make much stronger climate promises by the next big climate meeting (COP30) to avoid the worst damage.

Dr. Chris Stokes, who led a team studying polar ice sheets, said that even the current warming of about 1.2°C, if it continues, could cause sea levels to rise by several meters over the next few hundred years. This would cause serious damage to coastlines, making it nearly impossible for people living there to adapt.

Glaciers face a similar threat. Four key glacier areas—the European Alps, the Rocky Mountains in the U.S. and Canada, Iceland, and Scandinavia—are expected to lose at least half their ice if temperatures rise by just 1°C. If temperatures hit 2°C, these areas could lose nearly all their glacier ice.

Dr. Harry Zekollari, who led a team studying glaciers, said that if the world warms by 2.7°C (which is what current climate policies are on track for), only about 24% of today’s glacier ice would be left. But if warming is kept to 1.5°C, about 54% of glacier ice worldwide would survive, including 10-25% in the most vulnerable areas.

Zekollari stressed that staying close to the 1.5°C limit helps protect glacier ice almost everywhere, including 40-45% of the ice in places like the Himalayas and Caucasus mountains. This shows how urgent it is to meet this temperature goal by reducing carbon emissions quickly.

Even if we keep warming to 1.5°C, sea levels will still rise due to melting ice in Greenland and Antarctica, though more slowly than if temperatures reach 2.7°C. Some scientists believe that parts of the West Antarctic ice sheet are already starting to collapse, which would be irreversible.

To slow sea-level rise to safer levels, the world may need to aim for a long-term temperature increase of around 1°C or even less. Right now, about 230 million people live within just 1 meter of sea level, and 1 billion live within 10 meters—so melting ice is a serious threat to millions of people and several low-lying countries.

Both scientists strongly encourage countries to strengthen their climate action plans (called Nationally Determined Contributions or NDCs) at COP30 in Brazil this fall. They warn against risky “geo-engineering” ideas like spraying pollution into the atmosphere to cool the planet, which could make things worse.

“The best way to slow and stop warming is by cutting emissions,” said Zekollari. Stokes added, “With so little time left, the only real solution is to rapidly and steadily reduce carbon emissions to net zero.”