Even the current level of global warming may already have locked in unstoppable ice melt, with a major new study warning of several metres of sea level rise over the coming centuries.
Published in Communications Earth & Environment, the research says that just 1.2°C of warming above pre-industrial levels is enough to destabilise both the Greenland and West Antarctic ice sheets.
That means the widely accepted 1.5°C target may not be sufficient to prevent dangerous tipping points from being triggered.
The study brings together evidence from past climate periods, satellite observations, and ice sheet models.
It concludes that the current pace of change is already having a dramatic effect.
Ice loss has quadrupled since the 1990s and is now the biggest contributor to sea level rise, overtaking the thermal expansion of oceans.
Lead author Chris R. Stokes said: “Even current climate forcing (+1.2 °C), if sustained, is likely to generate several metres of sea-level rise over the coming centuries.”
One of the key concerns is that ice sheets don’t respond in a linear way.
Once a certain temperature threshold is passed, feedback mechanisms kick in—like warm water melting ice from below or surface meltwater speeding up glacier flow.
These can lead to runaway loss, even if global temperatures stabilise.
The researchers believe the safe limit for warming could be closer to 1°C than 1.5°C, meaning that the planet may already be beyond the point where long-term sea level rise can be avoided.
The conclusion is stark: reducing greenhouse gas emissions even faster may be the only way to slow down future impacts but some sea level rise is now inevitable.
The study is a warning shot for policymakers as low-lying regions face an increasingly uncertain future, regardless of short-term emissions cuts.
