In ‘The Day After Tomorrow’, humanity is frozen under layers of snow, drowned in massive tsunamis and dramatically crushed under vehicles thrown by tornadoes.
As it stands, this terrifying scenario – caused by a catastrophic climate shift triggered by global warming – is popcorn-worthy Hollywood sci-fi.
But a new study warns that it could become a reality in Britain by the end of this century.
Scientists at the University of Exeter and the Met Office say changes to North Atlantic winds could batter the UK with cold snaps, floods, and storms.
They point to the North Atlantic Oscillation (NAO) – a natural and temporary cooling and warming over parts of Europe and the North Atlantic ocean.
According to their findings, errors in current climate models have led to uncertainty in predictions of the NAO’s future behaviour.
Taking account of these errors reveals that the NAO could be disastrous for Britain, which is seriously underprepared.
‘These findings have major implications for understanding and preparing for extreme weather events,’ warned lead study author Dr Doug Smith at the Met Office.
In ‘The Day After Tomorrow’, humanity is frozen under layers of snow, drowned in massive tsunamis and dramatically crushed under vehicles thrown by tornados
Discovered through several studies in the late 19th and early 20th centuries, the NAO acts like a giant meteorological ‘see-saw’ in the North Atlantic.
It has two states – positive and negative – which both bring very different weather to Europe.
The positive phase happens when air pressure is low over Iceland, but high down south over the Azores islands (west of Portugal).
This resulting pressure difference drives strong westerly winds and weather fronts that crash into us, whipping up storms and sometimes causing floods.
A positive NAO on average can increase rainfall in northern Europe by a little over an eighth of an inch per day and warm the air there by roughly 5°F (2.8°C).
Meanwhile, a negative NAO occurs when the pressure difference between the two points is smallest, meaning less air movement overall.
Instead of winds from the west, winds from the east and north-east are more frequent, bringing with them cold air.
‘When the NAO is negative, there’s a greater chance of a snowier winter,’ said Met Office meteorologist Alex Deakin.
The North Atlantic Oscillation (NAO) is a weather phenomenon over the North Atlantic Ocean. It is measured by the gradient between high pressure over the Azores (west of Portugal) and low pressure over Iceland
Scientists say a negative North Atlantic oscillation (NAO) caused an unusually cold winter in Europe 15 years ago. Pictured, a driver tries to dig a car out from under the snow in Allendale, Northumberland, January 5, 2010
Blanketed with snow: This satellite picture shows the extent of snow cover across Britain and Ireland on January 7, 2010
A negative NAO can mean a big freeze, like the one of 2009-10 that caused transport chaos in Britain and was blamed for 90 deaths in Europe.
NAO in winter 2009-10 was lower than during any winter in over a century, resulting in more easterly winds bringing cold air into Northern Europe from Siberia and the Arctic.
‘The NAO severely impacts society, including through water security, flooding, mortality due to cold weather, transport, energy demand and supply, structural damage from storms and economic losses,’ say the team.
According to their new study, current prediction models have errors relating to the effect of water vapour, Earth’s most abundant greenhouse gas, on the NAO.
Correctly taking water vapour into account, NAO could reach unprecedented magnitudes, either positive or negative, by the end of the century due to global warming, they found.
Under a scenario of high emissions from fossil fuels, but in absence of major volcanic eruptions (which also release greenhouse gas), NAO will increase to unprecedented levels by 2100, 1.4 to 3.7 times greater than any in the historical period.
‘Our study suggests that taking model projections at face value could leave society unprepared for impending extremes,’ said Dr Smith.
‘Mitigation efforts are crucial to prevent the severe impacts associated with an unprecedented increase in the NAO.’
The team conclude that the NAO will ‘probably cause severe impacts on society’ – especially increased flooding and storm damage in Northern Europe
In their new study, published in Nature Climate Change, the team conclude that the NAO will ‘probably cause severe impacts on society’ – especially increased flooding and storm damage in Northern Europe.
However, they found a ‘clear capability’ for ‘mitigation’ to avoid such impacts.
The study also suggests that ‘taking model projections at face value’ could leave society ‘unprepared for impending extremes’.
‘Models cannot all be correct, and they must ultimately be improved to achieve reliable projections,’ they say.
‘Alternative recalibration approaches, such as those proposed here, are needed to prepare society for the full range of possible extremes.’
Is ‘The Day After Tomorrow’ an accurate portrayal of the future?
Paleoclimate records constructed from Greenland ice cores have revealed that AMOC circulation has, indeed, shut down in the past and caused regional climate change, according to the University of Illinois.
It caused the area around Greenland to cool by 44 degrees Fahrenheit.
In the 2004 film ‘The Day After Tomorrow,’ New York City’s temperature dramatically dropped to a point that a deep freeze appeared within a day.
Even a second outside and the movie’s characters would freeze to death.
Scientists say the film plays up the shift, which would take decades to see, but note temperatures would dramatically decrease along the eastern US coast.
In the 2004 film ‘The Day After Tomorrow,’ New York City’s temperature dramatically dropped to a point that a deep freeze appeared within a day. Scientists say the film plays up the shift, which would take decades to see, but note temperatures would dramatically decrease along the eastern US coast
Winters would become colder and storms more frequent that would linger longer throughout the year if the AMOC would come to a halt today.
However, scientist say it isn’t the cold temperatures that we should prepare for, it will be the rise in sea levels that will have the largest impact.
The increase would be caused by water piling up along the east coast that would have been pushed away by the northward surface flow.
But with AMOC weakened, or at a stop, experts say sea levels around the North Atlantic Basin could experience a rise up to nearly 20 inches.
This would eventually push people living along the coast from their homes and further inland to escape flooding.
A weakened AMOC would also decrease the amount of rainfalls in the North Atlantic that would cause intense droughts in areas that rarely experience such events.
