When the apocalyptic film first released, critics from both the entertainment and science communities ridiculed the movie over the possibility of climate change having such an extreme affect on the world. However, a recent study by researchers from the University of Southampton has found that we are closer to a “Day After Tomorrow” scenario than we thought.

In the film, climate warming results in the collapse of the Atlantic Meridional Overturning Circulation (AMOC) – a major current in the Atlantic Ocean that has a northward flow of warm, salty water in the upper layers of the Atlantic and a southward flow of colder water in the deep Atlantic. This leads to New York being flooded, tornadoes in Los Angeles, and finally the north hemisphere freezing and experiencing an Ice Age.

Researchers discovered that if global warming and the collapse of the AMOC occur at the same time, the Earth will cool for a period of 20 years. After the 20 years, global warming would continue as if the AMOC never collapsed and the global average temperature would offset by approximately 0.8 degrees Celsius. They used an advanced climate model at Germany’s Max-Planck Institute to simulate the conditions.

“The planet earth recovers from the AMOC collapse in about 40 years when global warming continues at present-day rates, but near the eastern boundary of the North Atlantic (including the British Isles) it takes more than a century before temperature is back to normal,” Professor Sybren Drijfhout, from Ocean and Earth Science Department at the University of Southampton, said in the release.

The AMOC depends on a connect of the warm north waters and the cool southern waters that flow deep in the North Atlantic. Due to global warming, the Greenland ice sheet has begun to melt into the AMOC, affecting the balance of the warm and cold waters. Currently, it is causing the AMOC to slow down, but it will eventually collapse.

While the climate sequence in the movie is sped up and exaggerated, the researchers still noted that the consequences from the AMOC collapse would be no less cause for worry.

The simulation showed that Western Europe would be hit the hardest by cold temperatures but America would have to contend with floods. Sea levels on the U.S. East Coast would rise more than three feet, and the UK, Denmark, and the Netherlands would see a 35-degree temperature drop.

“This would affect hundreds of millions of people,” Drijfhout said, “At least temporarily, Europe would suffer conditions that would look like the Little Ice Age of the Middle Ages.”

“When it comes to climate change, we are playing a dangerous game,” he added.