By Paul Homewood
A new study throws doubt on the theory that Arctic warming is man-made:
The Arctic Ocean has been warming since the onset of the 20th century, decades earlier than instrument observations would suggest, according to new research.
The study, published Wednesday in the journal Science Advances, found that the expansion of warm Atlantic Ocean water flowing into the Arctic, a phenomenon known as “Atlantification,” has caused Arctic water temperature in the region studiedtoincrease by around 2 degrees Celsius since 1900.
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.”
There is the inevitable attempt by the study author to link all of this to carbon dioxide, but as he himself admits there is no evidence for this.
But what this study does highlight is that it is the transport of warm Atlantic water which melted the sea ice and raised temperatures around the Arctic. GHGs only play a bit part.
As I have often pointed out, it is the world’s oceans which drive climate cycles. The study rather brushes over the Little Ice Age, , but it should surely have investigated whether the same Atlantification occurred during the MWP.
There’s a complex graph in the actual paper, but it’s worth homing in on the first section, the blue line (B), which plots “derived” sea surface temperatures in the Fram Strait.
Two things stand out:
- SSTs were higher than the 20thC for most of the AD 1300 to 1600 period.
- SSTs were as high in the early 20th as now.
We can also note the C chart, which measures the presence of sea ice around the Iceland coast. Climatologists, such as HH Lamb, have long known that the ice grew rapidly between AD 1600 and 1900. This is strong evidence that the LIA was an unusually cold era.
Lamb also believed that cooling began in Greenland as early as the 12thC.Therefore it is likely that SSTs would have been higher prior to the start of this new analysis in AD 1300.
Of course, the idea that Arctic warming since the 19thC is largely a natural phenomenon has huge ramifications. Not least the fear that the ice will one day return.
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NOVEMBER 27, 2021