Glaciers are not just blocks of ice — plans to save them mustn’t overlook their hidden life But regulations are urgently required before these fixes are used widely

As glaciers begin to disappear, technological fixes to slow or halt ice melt are emerging

Nearly half of Earth’s glaciers are projected to vanish by 2100, even if the increasingly improbable goal of limiting global warming to 1.5 °C above pre-industrial levels is met¹. Already, Venezuela and Slovenia have lost all their glaciers — the first countries to do so in modern times.

To draw attention to such losses and to highlight the crucial part played by glaciers, snow and ice in the climate system, the United Nations has declared 2025 as the International Year of Glaciers’ Preservation. Yet, there is remarkably little consensus on how to save a glacier.

Thirty years ago, when the UN Framework Convention on Climate Change came into force, the answer was clear: reduce greenhouse-gas emissions. Today, as carbon emissions continue to rise, mitigation alone seems to be insufficient. Technological interventions are starting to be explored — including making ice more reflective using tiny glass beads, enhancing snowfall through cloud seeding and wrapping glaciers in protective films and geotextiles².

However, glaciers are much more than frozen ice. Just like oceans and rainforests, glaciers and ice sheets are teeming with life³^–⁵. The glacial biome is composed mainly of microorganisms, and it is visible to the human eye only during colourful algal blooms. This microscopic ecosystem contains members of all three domains of life — archaea, bacteria and eukaryotes.

These microbes are far from typical, having genes that are adapted to extreme cold, scarce nutrients and oscillation between intense sunlight in summer and snow-covered darkness of winter. Some microorganisms found in the Tibetan glaciers, for example, seem to make antibiotics so that they can outcompete other ice-dwelling microbes⁵. This genetic potential has triggered interest in bioprospecting for antimicrobials and enzymes that can work at low temperatures⁶.

Glacier microbes have also been shown to accumulate and store heavy metals and other environmental pollutants, slowing the downstream release of these contaminants. Disruption to the glaciers’ microbial communities could therefore diminish their efficacy as contaminant buffers, with knock-on effects elsewhere in the environment.

As momentum builds for technical interventions to slow, halt and even reverse glacier melting, we argue that these must incorporate the complexity of the icy biome that they aim to preserve. Here, we outline the types of intervention that are being seriously considered, how to assess their impact and the regulatory guard rails that are urgently required.

Slowing ice melt

Localized interventions to preserve mountain glaciers fall roughly into two categories: those that aim to retain existing ice and those that promote the formation of fresh ice². So far, all have major, yet poorly studied, consequences for life on and inside the glacier. Serious academic investigations must begin before these techniques are adopted widely.

For example, researchers have tested the effect of spreading hollow microspheres, made of silica-based glass and 10–200 micrometres in diameter, on the ice of an Arctic lake⁷. The intervention increased surface reflectivity and therefore delayed melting. However, by blocking sunlight, such approaches could harm the algae and cyanobacteria present in the ice.

Reflective geotextiles on this small glacier in Switzerland helped to slow down melting.Credit: Matthias Huss

Another method is being trialled on Dagu Glacier in China: spreading a thin film of cellulose acetate — a synthetic material made from cotton or wood pulp⁸ — onto the ice. Initially designed for preserving frozen food, this material scatters incoming sunlight and thereby reduces melting⁸. However, its capability to mitigate glacier mass loss at scales larger than a few square metres, and its long-term sustainability and ecological impacts, have not yet been assessed.

Wrapping glaciers in reflective geotextiles (polypropylene, for example) can reduce ice melt by 50–70% per year⁹. Such synthetic blankets are already being used commercially — for instance, to save the artificial ice grotto of the Rhône Glacier in Switzerland. Although enveloping the ice in a blanket-like material does slow melting, it also blocks sunlight and nutrients.

Furthermore, polymer-based geotextiles release microplastics into the environment — first into the ice and then into downstream ecosystems. On an Austrian glacier where geotextiles have been used for nearly two decades, up to 3 kilometres of such microplastic fibres were recovered per square metre of ice. Small invertebrates ingest these microplastics, facilitating the entry of these particles into the food chain. Larger fibres can also entrap animals, mirroring many of the problems associated with marine plastic waste.

Approaches that aim to create fresh ice also have downsides. For example, in one small trial, researchers managed to seed snowfall from clouds over the Muz Taw Glacier in the Sawir mountains that span the border of Kazakhstan and China¹⁰. However, assessing this intervention’s efficiency is challenging because of difficulties in targeting its use and minimizing environmental costs.

Pumping water onto the ice and using snow cannons have also been suggested. These interventions were trialled on the Morteratsch Glacier in Switzerland¹¹. Test results show that they work in principle. However, their real-world implementation was abandoned owing to high cost, shortage of water resources and the lack of detailed environmental impact assessments.

Technical interventions on glaciers are in some ways reminiscent of large-scale climate geoengineering proposals, such as spraying particles into the upper atmosphere and carbon capture and storage. However, glacial interventions are almost exclusively local in application and effects if the implementation is robust. Although some cross-border issues might arise, they involve fewer ethical and governance challenges in general, making them more appealing for early adoption as the harmful effects of climate change ramp up.

Yet, the ecological consequences of these interventions have received hardly any attention from governments and policymakers. Furthermore, it is unclear what impacts these strategies would have on downstream communities, particularly on the supply of drinking water.

Glaciers can be inhospitable places to research and difficult to access.Credit: Feature China/Future Publishing via Getty

Currently available interventions are also expensive and hard to scale up, making them suitable only for the most economically valuable locations. Many glaciers are difficult to access. And interventions need to be repeatedly applied or renewed. Researchers have estimated a price tag of up to US$1.6 billion if all of the glaciers in Switzerland alone were to be blanketed¹².

It is a matter of concern that many of the early attempts to protect glaciers have been driven by commercial interests, in which incentives to disregard environmental concerns are high.