The Day After Tomorrow, a 20-year-old disaster movie that imagines the world plunged into a new Ice Age, could never become reality… could it?
The film, starring Dennis Quaid and Jake Gyllenhaal, depicts an Arctic apocalypse sweeping America and Europe. Its iconic images include Big Ben breaking through an ice sheet, as a glacier entombs London.
Despite its success, taking more than half a billion dollars at the box office, The Day After Tomorrow drew hoots of derision from even the most pessimistic weather-watchers.
Its central premise, that the Gulf Stream, a warm marine current that flows from the southern tip of Florida to Europe via the US eastern seaboard, could be on the point of collapsing due to melting ice from the Poles, was dismissed as lunatic scaremongering.
After all, a phenomenon that ensures the climate of western Europe is much more temperate than its latitude would dictate by wafting warm water (and air) across the Atlantic, has been with us for more than 10,000 years.
When the science writer David Wallace-Wells published an analysis of all the ways climate change could destroy civilisation in a book called The Uninhabitable Earth just five years ago, he envisaged rising sea levels, mega-hurricanes, rampant air pollution, mass human migration and economic madness.
But even Wallace-Wells couldn’t imagine that the Gulf Stream could be in imminent danger. ‘A shutdown of the ocean conveyor belt,’ he wrote, ‘is not a scenario that any credible scientists worry about on any human timescale.’
That complacency was wiped out this week when a group of 44 leading climatologists signed an open letter to the governments of Scandinavia, warning that the Atlantic Meridional Overturning Circulation (AMOC) – a system of ocean currents that brings warm water north and cold water south – could break down as early as next year, meaning the Gulf Stream would cease operating.
‘Given business as usual with greenhouse gas emissions, the expected tipping point is much earlier than previously predicted,’ says the author of a crucial report, statistics professor Susanne Ditlevsen of the University of Copenhagen. ‘We were actually bewildered by the result.’
AMOC is a vast natural phenomenon: 5.2billion gallons of seawater moving every second, almost 100 times greater than the Amazon river flow. But it is slowing fast due to greater quantities of cold fresh water flowing down from the Arctic as the polar ice caps melt.
This dilutes the salinity of the top layers of saltwater and prevents them from sinking to the bottom of the ocean, where they would normally drive the circulation back south.
Without the warmth the Gulf Stream brings from the tropics, Britain and much of Europe face a freeze on a scale unprecedented since the last major Ice Age or Pleistocene epoch, which lasted 2.6million years before ending roughly 11,000 years ago.
In the movie, timescales are condensed, with glaciers forming within days. That’s impossible, however impressive it looks on screen. But the real consequences, playing out across years instead of weeks, could be far more catastrophic than even Hollywood imagined.
Here we look at the dire possible impacts of a Gulf Stream collapse in 2025, winter by winter:
December 2025
As temperatures dip 5c below winter averages in the UK, bringing snowstorms and widespread travel chaos, climate experts and commentators are divided over the significance.
Many hark back to the record-breaking cold spells of 1947, 1963 and 1985, when remote areas were snowed in for weeks at a time and some weren’t fully thawed till Easter. This is a once-in-a-generation event, they claim.
Others urge governments to take action. It’s now too late to reverse climate change, they warn. The AMOC conveyor belt has been slowing since the 1930s and in 2010 a ‘cold blob’, midway between Britain and Newfoundland in Canada, was identified from satellite data.
The blob has been steadily growing and is now spreading across the whole Atlantic, bringing the Gulf Stream to a dead halt.
December 2026
The Thames freezes over for the first time in more than 60 years, the ice as far downstream as the Houses of Parliament.
Hundreds of people risk their lives to skate on it, and two teenagers die after falling through a hole in the ice. Police fence off the entire embankment on both sides.
Across the country, temperatures are regularly dipping well below zero, hitting a record low of minus 32c in Aviemore, Scotland.
The government refuses to reinstate the winter fuel allowance for pensioners, with Prime Minister Keir Starmer suggesting people wear jumpers and socks to bed instead of leaving the heating on. By Christmas, many councils have run out of grit and salt. Drivers are told to stay at home unless their tyres have snow chains. With the points frozen solid, several main rail lines are out of action.
In common with other European countries, Britain is forced to lift sanctions on Moscow in order to import Russian gas.
Oil is also in short supply, and petrol prices hit £3 a litre. A state of emergency is declared in January. Britain has shivered through five weeks of sub-zero temperatures without respite.
Hospital staff are sleeping on inflatable mattresses in offices and corridors as they can’t battle through the snow to get home. Patients can’t leave either, though hundreds of new cases struggle in every day – many with broken bones from falls on the ice. Merely feeding these people is an overwhelming challenge. Treating them is nigh impossible.
In February, with the Thames ice a foot thick, the first proper Frost Fair since 1814 is held, between Tower Bridge and Waterloo.
Frozen pipes leave hundreds of thousands of homes without running water, reliant on heating buckets of snow for drinking and cooking. Supermarket chains suspend home deliveries and Royal Mail announces it is too dangerous for their staff to stay working. But Amazon boxes still get through, brought by delivery men and women on skis pulling sleds.
Sir James Dyson launches an innovative electric snowmobile. Within days, he has taken more than a million orders.
June 2027
The first six months of the year are not only the UK’s coldest since records began but also immigration is rising tenfold. Although the UK has not seen a day above 18c, temperatures in the Middle East, parts of Africa and India are unbearable, hitting the 50s.
The world is splitting into two savagely different climate zones.
The monsoon season in South America and East Asia is shorter, the droughts longer, yet up to 43 per cent more rain falls during the wet periods.
Meanwhile, flooding in Brazil and Bangladesh is catastrophic, causing millions of deaths. But Scandinavia and the Baltic states are still iced over.
Townships of temporary housing are thrown up on the fringes of every major city, though they have no adequate sewage system, nor any basic facilities such as shops.
Families and friends cluster together in slum conditions. Inevitably, disease begins to spread – first respiratory conditions such as flu and Covid, then measles, TB and polio, and soon cholera and typhoid.
December 2027
Across the country, blizzards have been blowing for two months. Exposure and hypothermia are now the most common cause of death for both children and the over-60s.
All the major container ports, including Avonmouth and Felixstowe, are iced up. HMS Protector, the Royal Navy’s only icebreaker, is under repair, and for several weeks before Christmas no goods can be either exported or brought into Britain by sea.
Diesel is freezing in lorries, as are the batteries in electric vehicles, which are taking much longer to charge.
In the space of a single day, 20 motorists freeze to death in their vehicles after breaking down.
All this combined with severe restrictions on motorway traffic, with only a single lane open on most major roads (and these frequently blocked by accidents), the economy is in a recession deeper than anything seen even during the Covid pandemic lockdown. Inflation is above 1,000 per cent and rising.
Communications are also at breaking point. The BBC has been doing its best to reassure people via daily Covid-style bulletins on TV and radio fronted by Cabinet ministers and climate-change experts. But as the weather worsens, its infrastructure is coming under huge strain.
Underground fibre-optic cables are becoming brittle and cracking. Phone towers are buckling under the weight of ice and snow.
With electricity rationed to three hours a day for homes in urban areas, and internet connections patchy at best, working from home is now impossible for the majority of people – and commuting is equally out of the question.
Most non-essential industries have already given up trying to keep operating.
Agriculture is the most essential industry of all. But it, too, is at a standstill.
It is not just that tractor diesel has frozen. Barely 9 per cent of arable land produced a full crop this summer.
Livestock has been decimated, with tens of millions of cattle, sheep and pigs killed by the cold. In the space of three years, farming in Britain has become unsustainable – and the same is true in breadbasket nations such as the US and Ukraine.
Hotels and guest houses are wholly given over to housing refugees. With no food, no heating, no power and no staff, the restaurants and pubs are closed too.
Supermarkets shelves are empty, yet, every day, shivering queues stretch for 100 yards, hoping to buy whatever tinned supplies can be brought from warehouses. Fights break out hourly.
But shopping has become a dangerous business – organised gangs roam the streets, mugging people for whatever food they’re carrying, to be sold on the black market at extortionate prices.
Looting is now commonplace, sometimes descending into riots, with police powerless to halt it.
Since most stores are closed, with no one even to report the crimes, gangs strip whole streets of shops. They are taking electrical goods, home furnishings and designer clothing for the sake of it and then, often, dumping the spoils a few yards away because they are essentially valueless.
Many people barely venture out for fear of the gangs, as much as desperation to stay indoors where it is warmer. Despite this, the murder rate is 56 per cent higher than pre-Ice Age levels, as vulnerable people fight for shelter, food and warm clothing.
Families with children go door-to-door, begging to be taken in, and many are given room, especially by older couples and those living alone.
As well as being a brave, decent and generous act, the offer of a roof to strangers has a practical aspect – six people huddling in a room will be warmer than one or two.
December 2028
If the New Ice Age has not been overcome at this point, the projections become too grim to be imagined. Mass starvation and death from cold, lawlessness, political turmoil, war… all this is not merely a dystopian vision.
It’s the pattern of collapse brought on by climate disaster throughout history, from the disintegration of Saxon communities caused by a three-year freeze during the Dark Ages, to the social fragmentation in American cities, such as Chicago and New York, during the Polar Vortex of December 2022.
Yes, it reads like the scenario for another Hollywood disaster movie. We have to pray it’s one that never comes to pass.