According to recent research, Arctic Sea ice could soon be a thing of the past during summer. The ice melted at temperatures equivalent to the current temperature 10,000 years ago. This could have an impact on the climate and the ecosystems.
Icebreaker Oden in the sea ice north of Greenland. Image Credit: Martin Jakobsson, Stockholm University
In this time of rising temperatures caused by climate change, the “Last Ice Area” north of Greenland and Canada is the last refuge of all-year sea ice. A new study shows that this may be coming to an end soon.
Aarhus University researchers analyzed samples from the earlier inaccessible region north of Greenland in cooperation with Stockholm University and the US Geological Survey.
The sediment samples were taken from the sea bed of the Lincoln Sea, which is part of the “Last Ice Area.” They discovered that the sea ice in this region melted away around 10,000 years ago during the summer months. The study team concluded that summer sea ice melted when temperatures were at a level that is currently being rapidly approached.
Climate models have suggested that summer sea ice in this region will melt in the coming decades, but it’s uncertain if it will happen in 20, 30, 40 years, or more. This project has demonstrated that we’re very close to this scenario, and that temperatures only have to increase a little before the ice will melt.
Christof Pearce, Assistant Professor, Department of Geoscience, Aarhus University
The researchers used data from the Early Holocene period to forecast when sea ice would melt today. Summer temperatures in the Arctic were higher during this time period than they are nowadays. Although this was caused by natural climate variability rather than anthropogenic warming, it remains a natural laboratory for analyzing the fate of this region in the near future.
The marine samples were examined in Aarhus by Associate Professor Marianne Glasius and Academic Technical Staff Mads Mørk Jensen from the Department of Chemistry. They researched molecules from certain algae that are only produced when there is sea ice, among other things. As a result, the researchers can determine when summer sea ice was present in the area.
A Wake-Up Call
When the sea ice in the Lincoln Sea starts to melt during the summer months, it can have severe climate consequences. Whereas white ice reflects the sun's rays, a dark sea absorbs over ten times as much solar energy, contributing to global warming. Furthermore, it can have an impact on ecosystems:
The sea ice is a base for many ecosystems. The algae we examined are food for fish, fish are food for birds, etc. How will the marine ecosystems be affected globally if the sea ice disappears? We don't know the answer yet.
Henrieka Detlef, Assistant Professor, Department of Geoscience, Aarhus University
According to the Aarhus University investigators, the research can be perceived as good and bad news for the climate.
The bad news is that we can see this happening very soon. The good news is that our data shows the trend is reversible and we can do something about it if we reduce greenhouse gas emissions and set ambitious political goals. If we can keep temperatures stable or perhaps even make them fall, the sea ice would return to the area.
Henrieka Detlef, Assistant Professor, Department of Geoscience, Aarhus University
Christof Pearce reinforces stating, “The study is a wake-up call, because we know that it will happen. This news is not making the situation more depressing, just more urgent. We have to act now so we can change it.”
Journal Reference
Detlef, H., et al. (2023). Seasonal sea-ice in the Arctic’s last ice area during the Early Holocene. Communications Earth & Environment. doi.org/10.1038/s43247-023-00720-w.
Source: https://www.au.dk/en