New research reveals that mountain glaciers worldwide will not recover for centuries—even if the planet cools back down to the 1.5°C target after temporarily exceeding it. Led by the University of Bristol and the University of Innsbruck, the study presents the first global simulations projecting glacier change up to the year 2500 under ‘overshoot’ scenarios where temperatures peak near 3°C before stabilizing.
The findings, published in Nature Climate Change, show a temporary temperature overshoot of 3°C could result in glaciers losing up to 16% more mass by 2200. This is compared to a world that never crosses the 1.5°C limit. This loss is additional to the 35% glacier mass already committed under 1.5°C warming, contributing to long-lasting impacts on sea-level rise.
GLACIERS WON’T REGROW IN OUR LIFETIME—OR OUR CHILDREN’S
Dr Fabien Maussion, Associate Professor at the University of Bristol, explains: “It’s clear that such a world is far worse for glaciers. It is worse than one where the 1.5°C limit is held. Our findings indicate sadly not,” in response to whether they can recover soon if the planet cools again.
IMPLICATIONS FOR WATER SUPPLY AND COMMUNITIES
Smaller glaciers in regions like the Alps, Himalayas, and Tropical Andes are unlikely to recover before 2500. Large polar glaciers may take millennia to recover. Glacier meltwater is crucial for downstream communities, especially in dry seasons. The research highlights the phenomena of ‘peak water.’ This is when they shrink and there is increased meltwater release. Eventually, it is followed by ‘trough water,’ which occurs when regrowth reduces downstream flows. This affects water availability after 2100.
CLIMATE POLICIES AND THE URGENCY OF EMISSIONS CUTS
The study emphasizes the consequences of delayed emissions reductions and reliance on future negative emissions technologies like carbon capture. Overshooting the 1.5°C target locks in glacier loss for centuries, burdening future generations with irreversible environmental change.
RESEARCH CONTEXT AND FUTURE OUTLOOK
This research, part of the EU-funded PROVIDE project, combines novel global climate projections with an innovative open-source glacier model to provide the most comprehensive long-term outlook yet on glacier futures under climate overshoot scenarios.
Dr Maussion concludes: “The longer we delay emissions cuts, the more we burden future generations with irreversible change.”