Cryosphere.

“Cryosphere” refers to all regions on Earth where water exists in solid form – as snow and ice – permanently or seasonally. It is not only the planet’s largest freshwater reservoir, containing roughly two-thirds of global freshwater, or a regulating factor in the Earth’s climate, reflecting incoming sunlight. Once considered sterile and lifeless, we now recognise glaciers, snow, and polar ice sheets as thriving ecosystems, covering 10% of the Earth’s surface.

These icy ecosystems play a crucial global role. Microorganisms in snow and ice actively participate in carbon cycling, regulate the emission and sequestration of greenhouse gases, and thereby significantly influence Earth’s climate stability. Moreover, the cryosphere functions as a living archive, preserving the environmental conditions and microbial communities over thousands of years, offering invaluable insights into Earth’s ecological past.

As the climate warms, the delicate habitats within the cryosphere are disappearing. Melting glaciers and shifting snow cover lead to habitat loss and disruption of food chains, threatening biodiversity. Meanwhile, the thawing cryosphere releases previously trapped contaminants – microplastics, pesticides, antibiotic resistance genes, and even radionuclides – which can spread and impact ecosystems well beyond polar and alpine regions. Our research aims to better understand these critical ecological processes and ultimately guiding efforts to protect and preserve these unique ecosystems on a global scale.