Fossils From the Last Ice Age Could Help Us Understand the Impact of Global Warming on Arctic Ecosystems

22.09.2025

Fossilised animal remains uncovered in a Norwegian cave provide unprecedented insight into the wildlife of a warmer phase of the last Ice Age. Led by the University of Oslo, and with the participation of researchers from the Institute for Geological and Geochemical Research at the HUN-REN Research Centre for Astronomy and Earth Sciences (HUN-REN RCAES) and the HUN-REN Institute for Nuclear Research (HUN-REN ATOMKI), the team made an important discovery that sheds light on an Arctic ecosystem which disappeared around 75,000 years ago.

The Arne Qvamgrotta Cave, an excavation site on the northern coast of Norway, was discovered by chance in the 1990s during tunnel construction works in the surrounding mountains. Although the cave was identified three decades ago, it remained largely unexplored until recently, when systematic excavations were carried out in 2021 and 2022. Through meticulous fieldwork and laboratory analysis, the researchers successfully catalogued and dated the fossil remains, making it possible to reconstruct the past ecosystem in detail.

CSFK_jégkorszak — The team recovered animal remains from 12.8 metres of sediment.

The researchers’ newly uncovered, remarkable assemblage contains the remains of 46 different animal species, including mammals, birds and fish. It represents the oldest known assemblage of Arctic wildlife from this period in Europe.

Among the species identified are apex predators such as polar bears, as well as marine mammals including walruses and bowhead whales. The presence of seabirds such as puffins, eiders and ptarmigans points to a rich avifauna.

DNA analyses carried out on the fossils have provided new insights into the survival and extinction patterns of evolutionary lineages. Genetic evidence shows that animal populations which thrived during the interstadial warm period were unable to persist when colder Ice Age conditions later returned. This suggests that these species were highly adapted to the temperate Arctic environment characteristic of the warm phase, but lacked resilience to abrupt climatic shifts (cooling). These findings provide invaluable data for understanding how climatic fluctuations have shaped biodiversity in the Arctic.

Parallels between past and present

The researchers emphasise that species adapted to cold environments are now facing unprecedented challenges as a result of the rapid warming of the Arctic.

In contrast to conditions 75,000 years ago, the modern Arctic environment and habitats are severely fragmented by human activities and climate change. This fragmentation limits the ability of species to migrate and to adapt to changing habitats, increasing the risk of local extinctions and ecosystem collapse.

“This is a rare snapshot of a vanished Arctic world”

said Dr Sam Walker, a researcher at Bournemouth University and the University of Oslo, and lead author of the paper. He emphasised that these data on ancient wildlife help to improve our understanding of the resilience of species currently inhabiting the region and their vulnerability to climatic extremes.

Professor Sanne Boessenkool, the study’s other lead and a researcher at the University of Oslo, noted that before this discovery very little direct evidence was available about Arctic wildlife from this period, as scarcely any remains older than 10,000 years have survived. The diverse assemblage uncovered in the cave now bridges this critical gap in knowledge, providing insight into the composition of the marine and terrestrial megafauna of the interstadial period, thereby enriching our understanding of the palaeoenvironmental conditions of that time.

According to the researchers, understanding how species once responded to dramatic climatic fluctuations can help us predict the effects of current and future global warming on fragile Arctic ecosystems more accurately.