Climate change: Rainfall could replace Arctic snowfall by 2060, study warns
Rain could replace snowfall as the main form of precipitation in parts of the Arctic by 2060 thanks to climate change — up to two decades earlier than previously thought.
In the study, researchers at the University of Manitoba compared the latest forecasts with the results of previous climate models.
Precipitation levels are increasing in the Arctic, while rising global temperatures are melting increasing amounts of sea ice and adding moisture to the air.
The region is known to be warming faster than most other parts of the world, leading to significant environmental shifts in the region that will only worsen.
For example, an increase in rainfall on top of existing snow cover could contribute to the formation of more surface ice, preventing caribou and reindeer from foraging.
The effects won’t be limited to the Arctic, however, as the loss of snow cover reduces Earth’s ability to reflect sun rays into space, leading to more warming.
Based on the findings, the researchers are calling on authorities around the world to implement stricter climate mitigation policies.
Rain could replace snowfall as the main form of precipitation in parts of the Arctic by 2060 thanks to climate change — some two decades earlier than once thought
In the study, researchers from the University of Manitoba compared the latest projections with the results of previous climate models
What will happen to the Arctic?
“One of the first regions to be transformed from snowfall to rain as a result of this climate change is the Barents Sea, north of Russia,” said climatologist Andrew Shepherd of the University of Leeds.
The loss of sea ice in this area, he explained, “has already affected us by pushing Arctic weather fronts across Europe — like the Beast from the East.”
“We can also expect the Northern Sea Route to be used for shipping decades earlier, inevitably leading to more ships getting stuck by freezing ice, as happened this week.”
Speaking to AFP, Dr. Michelle McCrystall, who led the study, said: ‘Changes will be more severe and occur much earlier than expected and so will have huge implications for life in and beyond the Arctic.
“For example, in the fall, when the biggest changes occur, the central Arctic could transition into the latest set of models around 2070.”
This, she explained, is like “compared to 2090 in the previous set.”
In their study, the team analyzed the latest projections from the Coupled Model Intercomparison Project.
This simulates the Earth’s climate in such a way that the different parts of the model (such as the atmosphere and the oceans) can interact realistically.
Looking at how the water cycle in the Arctic could change by the year 2100, the researchers found that all forms of precipitation, including rain and snow, are expected to increase in all seasons as a result of global warming.
Rain will replace snow one to two decades earlier than previous models, depending on the area and seasons given — a change linked to increased warming and the faster decline of sea ice.
The transition to a rain-dominated Arctic may also occur at lower thresholds than predicted in previous models.
In some regions, including Greenland, such shifts could happen even after just 1.5°C of warming from pre-industrial levels — the most ambitious limit set by the Paris climate accord — she added. .
“The changes in the Arctic are already profound,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies.
“Changes will be more severe and happen much earlier than expected and so will have huge implications for life in and beyond the Arctic,” said Dr. McCrystall to AFP. Pictured: Expected changes in total precipitation (red), snow (blue), and rain (green) compared to the 1981-2009 climatic mean for different times of the year (for example, DJF is Dec, Jan, Feb)
In their study, the team analyzed the latest projections from the Coupled Model Intercomparison Project (CMIP). Shown: The differences in expected changes in snow and rain levels by the end of the century in the current and previous CMIP models — shown here for both December-February (top row) and September-November (bottom row)
‘The study shows that the effects are strongly linked to the overall rate of change in global temperature, and thus will depend on future greenhouse gas emissions.
“These results do not change the expected Arctic effects given a certain temperature increase, but do imply that the worst effects can be avoided if countries fulfill their stated intentions to reduce emissions, in accordance with the Paris agreement.”
“However, this cannot be taken as evidence that Arctic rainfall will increase ‘faster than expected’,” he warned — noting that some of the coupled models used have climate sensitivities greater than observations can be supported.
This leads on average to warmer future temperatures than can be expected and thus to earlier transitions for Arctic change.
“The IPCC predicts that the global temperature will rise significantly less rapidly than the CMIP6 ensemble means, and this projection does not take that into account. The claim of a new, “faster” prediction is not supported.”
The study’s full findings were published in the journal nature communication.
HOW DO RISING TEMPERATURES IN EUROPE’S ARCTIC COLD WEATHER CREATE?
As early as 1973, a study suggested that an ice-free Arctic Ocean could make regions further south colder.
That “warm Arctic, cold continent” (WACC) pattern is sometimes referred to as “wacc-y” or “wacky” by climate scientists.
When unusually warm air enters the region, the ice that covers the waters of the Arctic Ocean melts.
This ice normally serves as an insulator, stopping the flow of thermal energy from the water’s surface to the atmosphere.
Without the ice in place, the oceans can transfer a tremendous amount of this energy to the air above.
This in turn raises the air temperature and this warm air rises to the upper atmosphere, where it reaches the jet stream.
Jet streams are fast-flowing, narrow air currents that carry warm and cold air across the planet, much like the currents of a river.
They span thousands of miles as they meander near the tropopause layer of our atmosphere.
The strongest jet streams are the polar jets, which are found at the north and south poles 30,000 to 39,000 ft (5.7 to 7.4 miles / 9 to 12 km) above sea level.
In the case of the Arctic arctic jet, this fast-moving tire is between the cold Arctic air in the north and the warm, tropical air in the south.
When unequal masses of hot and cold meet, the resulting pressure difference causes winds.
In winter, the jet stream is usually at its strongest due to the clear temperature contrast between the warm and cold air.
The greater the temperature difference between the Arctic and tropical air masses, the stronger the jet stream winds become.
The Arctic polar jet, which can reach speeds of up to 200 mph (320 kph), flows across the mid to northern latitudes of North America, Europe and Asia and their intervening oceans.
It moves from east to west, although the exact route varies and can be influenced by several factors.
With the melting of ice in the Arctic and the introduction of warmer air, the jet stream’s route becomes more wavy and erratic.
That means the colder air it carries from the Arctic can penetrate further south and warmer air from the tropics is carried further north.
As the meander of the jet stream south of the UK collapses, it draws in cold air from the Arctic.
Conversely, when it swings north, it sucks warm air from the tropics.