The “Last Ice Age” in northern Greenland and Canada is the last shelter of year-round sea ice at this time of warming caused by climate change. Now a new study shows that this may soon be over. Researchers from Aarhus University, in collaboration with Stockholm University and the US Geological Survey, analyzed samples from a previously inaccessible region of northern Greenland.
Sediment samples were collected from the seafloor in the Lincoln Sea, which is part of the ‘Last Ice Shelf’. They showed that sea ice in the region melted in the summer about 10,000 years ago. The research team concluded that during the summer months, sea ice began to melt and temperatures were again at the level we are rapidly approaching today.
“Climate models suggest that summer sea ice in this region will melt in the coming decades, but whether that will happen in 20, 30, 40 years or more is unknown. This project has shown that we are very close to this scenario. “The temperature only needs to rise a bit before the ice melts,” says Christoph Pearce, Associate Professor of Geosciences at Aarhus University.
Researchers used early Holocene data to predict when sea ice will melt today. Summer temperatures in the Arctic during this period were higher than today. Although this was due to natural climate variability as opposed to human-induced warming, it is still a natural laboratory for studying the fate of this region in the near future.
At Aarhus, marine samples were analyzed in collaboration with Associate Professor Marianna Glasius and Academic Technical Staff Mads Merk Jensen from the Department of Chemistry. Among other things, they studied the molecules of certain algae that are only produced when there is sea ice. This way, researchers can determine when summer sea ice was found in the area.
wake up service
When sea ice in the Lincoln Sea begins to melt in the summer, it could have serious consequences for the climate. Where the white ice reflects the sun’s rays, the dark sea absorbs more than ten times the sun’s energy, thus exacerbating global warming. Additionally, it can affect ecosystems:
“Sea ice is the foundation of many ecosystems. The algae we are studying is food for fish, fish is food for birds, etc. How will marine ecosystems be affected globally if sea ice is lost? We don’t know the answer yet,” says Henrika Detlef, associate professor in the Department of Earth Sciences.
According to researchers from Aarhus University, the research can be interpreted as both good and bad news for the climate.
“The bad news is that we will see that happen very soon. The good news is that our data shows the trend is reversible and we can do something about it by reducing greenhouse gas emissions and setting ambitious policy targets. If we can keep temperatures stable or even lower, sea ice will return to this region. will be back,” says Henrika Detlef.
This was echoed by Christophe Pearce: “The study is a wake-up call because we know it will happen. This news doesn’t make the situation more depressing, it just makes it more urgent. We must act now to change that.”
Source: Port Altele
