Icelandic glaciers have been losing mass since the Little Ice Age, but that process has slowed over the last decade thanks to the influence of what scientists have dubbed the Blue Blob, “an area of regional cooling in the North Atlantic Ocean to the south of Greenland,” Euronews reports. This was among the findings in a new study authored by Icelandic and Dutch scientists, who also project that the slowdown is only temporary.
When less snow accumulates on glaciers in the winter than melts in the summer, this is called Negative Surface Mass Balance, or SMB, which in turn, causes sea levels to rise. In Iceland, this process accelerated at the start of the 21st century but has slowed down considerably since 2011. This is particularly surprising because loss of mass has not slowed down for glaciers in nearby Arctic areas—most notably the Greenland Ice Sheet, which has been identified as the single greatest contributor to rising sea levels. In the span of 12 months alone, from August 2020 to August 2021, the Greenland Ice Sheet lost close to 166 billion tonnes of ice.
In the course of their research, the Icelandic-Dutch team noted that the slower rate at which Icelandic glaciers have been losing mass coincided with the emergence of the Blue Blob. As Iceland is “more exposed to the ocean and maritime influences than Greenland,” the scientists say that it now “appears that a cooler convection of air from the blue blob has kept [Icelandic] glaciers more intact.
The mystery of the Blue Blob
The Blue Blob is a mystery in and of itself, and one which scientists have sought to explain for years. Over the last 100 years, global temperatures have risen by an average of 1°C, but at the same time, the temperature of the Blue Blob has dropped, in almost direct proportion, by .9°C. One hypothesis for this is that the North Atlantic current has gotten weaker, which means that Nordic waters are getting less of an infusion of warm water from the tropics. Back in 2016, Norwegian climate researcher Peter Langen offered quite a simple explanation: the blob came into being during a very cold winter, he said, “and the cold actually resulted in an increased mixing of surface water with the deeper levels.” Most recently, in 2020, it was postulated that human-created factors caused the cold spot, namely low-level clouds that deflect sunlight.
Whatever its origin, the Blue Blob’s effect on Icelandic glaciers is clear. But while it has slowed SMB in Iceland’s glaciers for now, scientists say this won’t last forever. The research team conducted climate modeling that took into account both satellite images and fieldwork findings. Their model showed that there will be a short window in the 2040s when Icelandic glaciers “actually go back to an SMB of zero,” but by the 2050s, “global warming will flip the narrative.”
Icelandic glaciers could lose up to a third of their volume by end of 21st century
The Blue Blob will eventually stop cooling, the scientists say, and at that point, Icelandic glacier ice will begin to melt even faster. If there is no intervention to curb climate change, by the end of the 21st century, Icelandic glaciers will have lost a third of their total volume. And this could easily have “disastrous consequences around the world.” The projections are not entirely without hope, however.
“The Arctic is warming fast, and it can be difficult to live with” lead author Brice Noël, a post-doc researcher at the Institute for Marine and Atmospheric research in Utrecht, told Euronews. “But climate projections give us trajectories that enable us to see what needs to be done to try and mitigate glacier melt.”
See the full study (in English) here.
