The Arctic is warming nearly four times faster than Earth’s average – up to twice as fast as previously reported, a new study shows.
Researchers have analyzed multiple datasets from organizations including NASA and the Met Office on Arctic Circle temperatures between 1979 and 2021.
They found that much of the Arctic Ocean was warming at a rate of 0.75 °C (1.35 °F) per decade during this period, almost four times faster than the global average.
Previous studies report that the Arctic is warming, on average, either twice, more than twice, or three times as fast as Earth.
These estimates have been widely reported in the literature and media, but they are “significant underestimates” despite being based on “state-of-the-art” computer models, the authors say.
Temperatures in the Arctic are warming faster than the rest of the world, largely due to the loss of sea ice.
As bright and reflective ice melts, it gives way to a darker ocean. This amplifies the warming trend as the sea surface absorbs more heat from the sun than the surface of snow and ice.
The Arctic is warming nearly four times faster than the rest of the world, a new study shows. Pictured are melting sea ice floes in still waters of the northern Arctic
Researchers have analyzed observational datasets from organizations including NASA (Gistemp) and the Met Office (HadCRUT5) on Arctic Circle temperatures between 1979 and 2021. This graph shows the evolution of the annual average temperature in the Arctic (bold colors) and worldwide (faint colors). . Temperatures are calculated relative to the 1981-2010 average
Why is the Arctic warmer?
As early as 1896, Swedish scientist Svante Arrhenius hypothesized that changes in the concentration of carbon dioxide in the Earth’s atmosphere could alter surface temperatures.
He also suggested that the changes would be particularly large at high latitudes, even more so than in the tropics.
In recent decades, warming has been strongest in the Arctic — known as “Arctic amplification.”
Researchers in Finland now say the Arctic amplification is more extreme than previously reported.
In 43 years, the Arctic has warmed almost four times faster than the global average.
In recent decades, warming has been strongest in the Arctic – a phenomenon known as “Arctic amplification”.
The magnitude of Arctic amplification is influenced by both human-induced climate change and natural long-term climate variability.
According to the study, both factors may have led to an increase in amplification over the past 43 years.
The new study was led by researchers from the Finnish Meteorological Institute and published in the journal Communications Earth & Environment.
“In recent decades, warming in the Arctic has been much faster than in the rest of the world, a phenomenon known as Arctic amplification,” they say.
“Numerous studies report that the Arctic is warming on average either twice, more than twice or even three times as fast as the Earth.
“Here, using multiple observational datasets covering the Arctic region, we show that the Arctic has warmed nearly four times faster than Earth over the past 43 years, a higher ratio than commonly reported in the literature.”
For the study, the team compared observational data from a range of climate datasets, including the Met Office’s HadCRUT5, NASA’s Gistemp and Berkeley Earth from the nonprofit organization of the same name.
Previous studies report that the Arctic is warming, on average, at either twice, more than twice, or three times the rate of the globe, but these are underestimates, the researchers say (file photo).
The trend in annual mean temperature for 1979-2021 (left) and the trend in annual mean temperature relative to the global mean (Arctic amplification, right)
Although there is debate as to where the Arctic begins and ends, the team defined the Arctic region as the area inside the Arctic Circle.
Meanwhile, the rate of warming has been calculated from 1979, when more detailed satellite observations became available.
“The Arctic was defined using the Arctic Circle because we wanted to use an area that most people perceive as the Arctic,” said study author Mika Rantanen, a researcher at the Finnish Meteorological Institute.
“We focused on a period beginning in 1979 because observations after that year are more reliable and because the strong warming began in the 1970s.”
Researchers found that the Arctic is warming four times faster than the global average, but even more at the local level.
For example, in the Barents Sea area between the Svalbard and Novaya Zemlya archipelagos, it was seven times higher than the global average.
A map of the Arctic with the Arctic Circle – an area most people perceive as the Arctic – in blue. Also circled is the Barents Sea area, where warming is seven times the global average
Pictured is a polar bear on a melting ice floe in the Arctic Sea. Arctic temperatures are warming faster than the rest of the world, largely due to loss of sea ice (file photo)
The study also showed that climate models struggle to simulate the fourfold warming rate of the Arctic region.
This could mean that climate models systematically underestimate Arctic amplification, or that the current warming situation is simply considered too unlikely an event for a computer model.
The team admits that the extent of Arctic amplification depends on how the Arctic region is defined and the time period studied.
Almost independently, however, climate models have been found to underestimate Arctic amplification, they report.
“Our results require a more detailed investigation of the mechanisms behind AA [Arctic amplification] and their representation in climate models,’ the team concludes.
MELTING ARCTIC ICE COULD OPEN UP NEW ECO-FRIENDLY SHIPPING
From wildfires to melting glaciers, the negative effects of climate change are well documented, but a new study suggests there could be at least one positive effect.
Researchers say parts of the Arctic that were once covered in year-round ice will be reliably ice-free for months in just two decades due to global warming.
A result of this could be shorter, greener maritime trade routes that bypass the Russian-controlled North Sea Route.
This would reduce the shipping industry’s carbon footprint and weaken Russia’s control over trade routes through the Arctic, they say.
Examples of routes through the Arctic made navigable by melting ice are the Transpolar Sea Route and the Northwest Passage.