EPFL · Wetenschap

Retreating glaciers are taking entire worlds with them

Switzerland is losing approximately 40% of its glacial reserves, impacting not only water and energy resources but also undiscovered living ecosystems. Researchers from EPFL are highlighting the scope of this issue, with projections suggesting Switzerland could be nearly glacier-free by 2050-2070.

Glacier melt is a significant concern, with over 1,100 of Switzerland's small glaciers disappearing since the early 1970s. Remaining glaciers have lost 40% of their volume since 2000, shrinking from 75 km3 to an estimated 45 km3 by the end of 2025. This rapid decline poses environmental, economic, and landscape challenges, particularly for Switzerland's energy supply, which relies heavily on hydropower.

Giovanni De Cesare, an engineer at EPFL, explains that the loss of glaciers will disrupt the steady summer runoff, forcing reliance on unpredictable precipitation. The Grande Dixence dam, for example, could see a 30% reduction in glacier-fed inflow by the century's end, impacting its ability to compensate for seasonal variations. To mitigate this, raising existing dam heights is proposed as a more feasible solution than building new ones, with several projects already underway or under consideration.

Dams also face sedimentation issues, with increasing morainic deposits reducing reservoir capacity. Solutions like sediment bypass systems exist but are costly and rarely integrated into initial designs. De Cesare suggests that future dams should serve multiple functions beyond power generation, including irrigation, artificial snow production, and flood protection.

Beyond water resources, glaciers harbor diverse microbial ecosystems. Tom Battin, a professor at EPFL, studies these microorganisms, which have adapted to extreme conditions. As glaciers melt, mountain streams are warming and becoming clearer, leading to a shift from gray to green ecosystems with the proliferation of algae. This "green transition" offers a glimpse into Switzerland's future, potentially leading to a loss of unique biodiversity and genetic resources.

To preserve this biological heritage, initiatives like the Microbial Initiative for the Cryosphere aim to create a biobank of glacial microbes for study and potential biotechnological applications. Similarly, the Ice Memory initiative collects ice core samples from threatened glaciers worldwide for long-term storage in Antarctica, preserving a historical record of Earth's climate and atmosphere.

Both De Cesare and Battin emphasize the urgency of action, highlighting the long-term consequences of contaminating groundwater reserves and the irreversible loss of biodiversity. The Mount-Resilience project is exploring how mountain regions can adapt to climate change by integrating scientific data with local stakeholder input, aiming to foster better decision-making regarding natural resources.

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