Tree beneath glacier shows shifting Alpine past
A peer-reviewed study dates trees near the Morteratsch Glacier to between roughly 10,800 and 10,350 years ago.
Researchers have examined a tree near Switzerland’s Morteratsch Glacier that grew in a place later covered by ice. The find shows that the local glacier temporarily retreated further than it does today in the early Holocene, but it is not a direct global temperature measurement.
The European larch examined was exposed in 2025 beside the retreating Morteratsch Glacier in Switzerland’s Engadin. The tree had preserved roots and lay close to the place where it had grown. This enabled the researchers to assess more reliably whether the wood had been moved or had been covered in situ by a later glacier advance.
The study appeared in E&G Quaternary Science Journal, an open-access journal for Quaternary research. Using tree rings and radiocarbon dating, the researchers placed the tree’s final year of growth at around 8350 BC. According to the study, another tree from the area began growing about 10,800 years ago.
Taken together, the finds point to a local glacier minimum that lasted for at least several centuries. During that period, the area around the present glacier edge was suitable for tree growth. The ice then advanced again and covered the trees. The research thus reconstructs the history of one glacier system, not Europe’s climate as a whole.
That distinction is important. A tree at an altitude of 2,150 metres can provide information about the local ice margin, soil formation and growing conditions. It does not directly say how much warmer the entire Earth was, nor what caused conditions to change at the time. The authors therefore warn against using the find as a simple comparison with today’s human-caused warming.
The study forms part of a broader series of investigations into tree remains, moraines and ice layers in the Alps. Such sources supplement instrumental measurements, which have only been available for a few centuries. They can show that glaciers grew and shrank several times during the Holocene, but they also provide different kinds of information with varying degrees of uncertainty.
The current significance lies chiefly in the contrast between pace and cause. The fact that the Alps experienced periods with less ice in the past is compatible with natural climate variability. It does not mean that the rapid recent retreat of glaciers has the same cause. Modern measurements, greenhouse-gas data and climate models are needed for that.
Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The dating, location and research method can be found in the publication and the institutional record. The text preserves the key limitation: local glacier history is not a global temperature measurement.
- confirmed The tree was exposed beside the Morteratsch Glacier. — The study and summary describe the find from 2025. source
- confirmed The final year of growth was around 8350 BC. — The research description gives this date. source
- confirmed Another tree began growing about 10,800 years ago. — This is stated in the study summary. source
- confirmed The find is not a direct global temperature measurement. — The source makes this limitation explicit. source
Editor's note
The research is peer-reviewed, but the study concerns local glacier history. The find does not provide a direct global temperature reconstruction.Sources
- Tree growth at the beginning of the Holocene at an elevation of 2150 m in the Engadin Valley — E&G Quaternary Science Journal
- Tree growth at the beginning of the Holocene at an elevation of 2150 m in the Engadin Valley — FAU CRIS
- Tree growth at the beginning of the Holocene at an elevation of 2150 m in the Engadin Valley — Climate Events
More on this in Dutch media
- NOS — „alpen morteratsch”
- Het Parool — „alpen morteratsch”
- Trouw — „alpen morteratsch”