Francesco Muschitiello, an author on the study and assistant professor of geography at the University of Cambridge, said the findings were worrisome because the early warming suggests there might be a flaw in the models scientists use to predict how the climate will change.
“The Arctic Ocean has been warming up for much longer than we previously thought,” Muschitiello told CNN. “And this is something that’s a bit unsettling for many reasons, especially because the climate models that we use to cast projections of future climate change do not really simulate these type of changes.”
The researchers used marine sediments in the Fram Straight, where the Atlantic meets the Arctic east of Greenland, to reconstruct 800 years of data that paint a longer historical picture of how Atlantic water has flowed into the Arctic. The marine sediments are “natural archives,” the researchers wrote, which record data on past climate conditions.
Researchers found temperature and salinity, the saltiness of ocean water, remained fairly constant up until the 20th century — then they suddenly increased.
“The reconstructions suggest a substantial increase in the Atlantic Ocean heat and salt transport into the Nordic Sea at the beginning of the 20th century, which is not well simulated by (climate models),” Rong Zhang, a senior scientist at NOAA’s Geophysical Fluid Dynamics Laboratory, who was not involved with the study, told CNN. “It’s important to understand the cause of this rapid Atlantification, as well as the discrepancies between the model simulations and the reconstructions.”
Muschitiello said it’s not clear how much of a role, if any, human-caused climate change played in the early Arctic warming, and more research is needed.
“We’re talking about the early 1900s, and by then we’ve already been supercharging the atmosphere with carbon dioxide,” he said. “It is possible that the Arctic Ocean is more sensitive to greenhouse gases than previously thought. This will require more research, of course, because we don’t have a solid grip on the actual mechanisms behind this early Atlantification.”
The rapidly warming temperatures in the Arctic have caused sea ice to melt, which in turn causes more warming — while bright white sea ice reflects the sun’s energy, dark ocean absorbs the energy as heat.
James E. Overland, NOAA Arctic scientist based at NOAA Pacific Marine Environmental Lab in Seattle, said such long-term changes in the North Atlantic, coupled with recent loss of sea ice in the Arctic, threatens marine ecosystems.
“Loss of sea ice and ocean currents has shifted the buffer region between the Atlantic and Arctic Ocean to something closer to an arm of the central Atlantic,” Overland, who was not involved with the study, told CNN. “Important fisheries and marine mammals are vulnerable to ecosystem reorganization from such Atlantification.”
“When I talk to my students I always try to make them aware that the Arctic is warming very, very quickly, and much faster than any other area on the planet,” Muschitiello said. “It’s very unsettling and very troubling, especially because we still don’t have a full understanding of feedbacks at play.”
“We’re still slowly getting to know how the whole system works,” he said. “And my fear is that by the time that we do crack the problem, it’s going to be too late.”
For Latest Updates Follow us on Google News
**If you have any Query Related This Post then here is the Source Link**