Climate change caused by human activity is expected to make extreme cold snaps less frequent in Northern Europe, but paradoxically they may become more dangerous, a study published on Wednesday said.

Not only will milder weather lead populations to drop their guard, but temperature fluctuations cause greater wear and tear on infrastructure, according to the new study conducted by researchers at the World Weather Attribution (WWA).

Finland, Norway and Sweden experienced a major cold wave in January that broke several records.

The town of Vittangi in northern Sweden registered the lowest temperature recorded across the three countries since the start of the century, at -44.6C (-48.3 F).

In Oslo, the mercury fell below -30C for the first time, dropping to -31.1C.

Attributed to Arctic air flows and clear skies, the cold snap disrupted transport, damaged water pipes, and closed schools, as the price of electricity, a common heating source in the region, skyrocketed.

On a planet that is 1.2C warmer than during the pre-industrial era, such incidences are growing increasingly rare in Northern Europe.

Nowadays, five-day cold snaps and a day of extreme cold are five and 12 times less likely, respectively, said the team of 19 international researchers.

"On a warming planet, cold waves are becoming less intense and less frequent," said Izidine Pinto, researcher at the Royal Netherlands Meteorological Institute.

"However, this isn't cause for celebration," he warned.

– Vulnerable populations –

Less frequent cold snaps could lead the Nordic countries — currently accustomed to extreme cold — to let down their guard, the scientists cautioned.

"Cold waves are still an important risk for the region," Dorothy Heinrich, climate risk advisor at the Red Cross Red Crescent Climate Centre said.

"Even if they are occurring less frequently on average, future ones could possibly become more impactful if risk perception and preparedness decrease," she said.

Like other extreme weather incidents, cold waves can have fatal consequences for vulnerable and fragile populations.

"Older people, children, people who live in poor housing, and people who are experiencing energy poverty or homelessness are particularly vulnerable to these cold temperatures," said Heinrich.

Temperature fluctuations above and below freezing also bring other problems.

"The constant freezing and thawing of water comes with challenges for infrastructure and road safety," said Erik Kjellstrom, a climatologist at the Swedish Meteorological and Hydrological Institute (SMHI).

"It can also create a more layered snowpack that increases the risk of avalanches and reduces access to food for reindeers and other animals," he said.

– 'Arctic amplification' –

North of the Nordic countries, rising temperatures have melted sea ice which, in turn, contributes to accelerated warming in the region.

According to a study published in 2022 by Finnish and Norwegian researchers, the Arctic has warmed almost four times faster than the rest of the world since 1979, a phenomenon known as "Arctic amplification".

"Until we move away from fossil fuels and reduce emissions to net zero, climate change will continue to make earth a harsher place to live," said Sjoukje Philip of the Royal Netherlands Meteorological Institute.

At the COP28 climate summit in Dubai in December, the international community agreed to transition away from fossil fuels.

But oil and gas producing countries — including Norway — continue to award exploration licenses, delaying the energy transition called for by scientists and climate activists.