A joint team from the Franco-Swiss Alpine regions has published an article in Nature exploring the natural areas that will be exposed by retreating glaciers between now and 2100, calling for recognition of this unique character and the services these areas provide to humanity.
What happens with the space freed up by glaciers? The glaciers bordering the gigantic Antarctic ice sheet and the great Greenland ice cap, the glaciers of the other Arctic regions, and those around the high peaks of the planet’s six main continents cover an area of 650,000 km2, the size of the United Kingdom and Norway combined.
These glaciers, which are highly sensitive to current climate change, will retreat by half if the use of fossil fuels is not controlled. If anthropogenic emissions remain low enough to be compensated for by absorption of ecosystems in action across the planet, they will only retreat by a quarter of their surface area, as shown once again in an article in the journal Nature published last Wednesday, the results of which go even further this time.
“Post-glacial” ecosystems, using the authors’ expression, emerge following the retreat of the ice. Forests, freshwater ponds, lakes, meadows and even underwater ecosystems replace glacial and floating ice tongues. After modelling the retreat between now and 2100, 78% of the cleared areas will be land, 8% will form freshwater wetlands and 14% will open up marine zones.
As Jean-Baptiste Bosson, the study’s main author, points out, the polar regions in particular are more likely to see the emergence of underwater ecosystems, as “the mountains located near the sea feed the massive glaciers that float on its surface”. In Antarctica, the Russian Arctic and Svalbard, they will represent 16,200 km2 of coastal space.
In Alaska and on the fringes of Greenland, rivers and lakes are more likely to emerge, totalling 4,270 km2. Iceland and Scandinavia are following the same trend.
Scientists call for sanctuary
These post-glacial ecosystems are largely untouched, an unequalled rarity in a world where natural areas are largely modified or artificialized by human activity. Yet global warming is exacerbating the extreme weather events that biodiversity and agriculture have to face, accentuating social tensions. In this context, most of these pristine areas are under threat and have no special status to escape pollution, species introduction, mining, tourism, hydroelectric production, agriculture, fishing, hunting and civil engineering developments.
At the same time, it’s now possible to attribute value to them. These new ecosystems absorb CO2 through photosynthesis and other processes, thereby mitigating climate change. Estimates of this benefit range from 45 Mt to 85 Mt over the course of the 21st century for submerged land.
Wetlands store around 2% of the freshwater released by glaciers, limiting its flow to the sea and thus the risk of flooding. In polar regions, they also provide refuges for cold-adapted species.
This mechanism of disappearance of ice and appearance of new spaces is also a powerful lever for raising collective awareness: “A citizens’ initiative in Switzerland is successfully using the protection of glaciers in 2023 to change national laws and stimulate action in favour of the climate”, they point out.
The researchers note that 30% of these new areas have protected status, including high alpine sites classified by UNESCO and the Antarctic Treaty, but that the Arctic is much less protected, particularly in Canada and Siberia.
The authors therefore call for these new areas to be added to the international nature conservation agenda. They emphasize the effectiveness of such protection measures, which “seem easy, inexpensive and beneficial” to the “urgent need for climate change mitigation.”
The scientists believe that the “law of ecosystems” should be promoted and protective measures developed for post-glacial natural areas, banning all human activity or at least limiting it to the most sustainable ones, as in the case of certain UNESCO sites.
In this respect, the study calls on the UN’s intention back in 2022 to make 2025 the “International Year of Glacier Preservation”.
Camille Lin, PolarJournal
Featured image by Minik Rosing
Link to the study and related publications :
- Bosson, J.B., Huss, M., Cauvy-Fraunié, S., Clément, J.C., Costes, G., Fischer, M., Poulenard, J., Arthaud, F., 2023. Future emergence of new ecosystems caused by glacial retreat. Nature 620, 562-569. https://doi.org/10.1038/s41586-023-06302-2
- Lecomte, N., 2023. The great melt will shape unprotected ecosystems. Nature 620, 499-500. https://doi.org/10.1038/d41586-023-02490-z
- Tollefson, J., 2023. Melting glaciers will reveal vast new ecosystems in need of protection. Nature. https://doi.org/10.1038/d41586-023-02564-y
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