In the 2004 film ‘The Day After Tomorrow’, humanity is plunged into a nightmarish international storm that sends the planet into a new Ice Age.
And although the blockbuster was relegated to the realm of science fiction, the science behind the terrifying scenario is true.
Within decades, melting glaciers could close the Gulf Stream, the system of currents that brings heat to the Northern Hemisphere, experts say.
Without this additional heat source, average temperatures could drop several degrees in North America, parts of Asia and Europe, and people would see “severe and cascading consequences around the world.”
An abrupt shutdown of Atlantic Ocean currents appears more likely than ever, scientists warn, as computer simulations find a “cliff-like” tipping point looming in the near future.
In some parts of Europe, the collapse of a large ocean current system called AMOC could cause a temperature drop of more than 5.4°F (3°C) every 10 years.
In the Hollywood blockbuster ‘The Day After Tomorrow’ (pictured), ocean currents around the world stop as a result of global warming, triggering a new Ice Age on Earth.
The study’s authors, from Utrecht University in the Netherlands, don’t know exactly when the collapse will occur, although a previous study put it next year.
“We are getting closer to collapse, but we are not sure how much closer,” said lead author René van Westen, a climatologist and oceanographer at Utrecht University.
“We are heading towards a turning point.”
According to van Westen, when a global climate catastrophe like the one in ‘The Day After Tomorrow’ can occur is “the million-dollar question.”
“Unfortunately we cannot respond to that at this time,” he said.
“It also depends on the rate of climate change we are causing as humanity.”
The Gulf Stream is part of a much larger system of currents, officially called the Atlantic Meridional Overturning Circulation or AMOC.
Described as “the conveyor belt of the ocean”, it transports warm water near the ocean’s surface northward, from the tropics to the northern hemisphere.
When warm water reaches the North Atlantic (around Europe, the United Kingdom, and the east coast of the United States), it releases heat and freezes.
As this ice forms, salt is left in the ocean water.
Due to the large amount of salt in the water, it becomes denser, sinks and is carried south into the depths.
Eventually, the water returns to the surface and is heated in a process called upwelling, completing the cycle.
Scientists believe AMOC brings enough heat to the Northern Hemisphere that without it, much of Europe could freeze over.
Formally known as the Atlantic Meridional Overturning Circulation (AMOC), it drives the Gulf Stream that brings warm water from the Gulf of Mexico to the northeastern US coast.
Previous studies have already shown that due to climate change, the AMOC is slowing down.
The engine of this conveyor belt is off the coast of Greenland, where, as more ice melts due to climate change, more fresh water flows into the North Atlantic and slows everything down.
The new study predicts that an abrupt closure of the AMOC could occur in the coming decades, rather than in the next few centuries as previously thought.
The researchers designed a computer simulation in which they were able to measure a sudden weakening of ocean circulation.
The simulation introduced fresh water into the Atlantic Ocean and, as a result, the strength of the circulation gradually decreased until it reached a critical “tipping point” and collapsed.
According to the results, the European climate will cool by about 1.8°F (1°C) per decade, and some regions will even experience cooling of more than 5.4°F (3°C) per decade, much faster than current global warming of about 0.36 F (0.2 C) per decade.
In addition to plunging countries into a deep freeze, this would extend Arctic ice further south, further increase heat in the Southern Hemisphere, change global rainfall patterns and disrupt the Amazon rainforest.
Other scientists say it would be a catastrophe that could cause food and water shortages around the world.
AMOC Collapse: Would change climate around the world because it means the shutdown of one of the planet’s key climate and ocean forces. It would drop temperatures in northwestern Europe by 9 to 27 degrees (5 to 15 degrees Celsius) over decades.
“We found that once the tipping point is reached, the conveyor belt stops after 100 years,” the authors say.
“Northward heat transport is greatly reduced, causing abrupt climate changes.”
The only thing they couldn’t identify is when exactly this tipping point will be reached, although it is at least decades away, if not longer.
“The research convincingly demonstrates that the AMOC is approaching a tipping point based on a robust, physically based early warning indicator,” said Tim Lenton, professor of climate change at the University of Exeter, who was not involved in the study. the study.
“What it can’t (and doesn’t) say is how close the tipping point is, because it shows there isn’t enough data to make a statistically reliable estimate of that point.”
The study has been published in the journal Scientific advances.