Could 'The Day After Tomorrow' happen?

London: Did you find it hard to believe the climate scenario featured in the disaster movie 'The Day After Tomorrow'? Now, a researcher has produced a scientific study of the scenario.

In the 2004 film, climate warming caused an abrupt collapse of the Atlantic Meridional Overturning Circulation (AMOC), leading to catastrophic events such as tornados destroying Los Angeles, New York being flooded and the northern hemisphere freezing.

Although the scientific credibility of the film drew criticism from climate scientists, the scenario of an abrupt collapse of the AMOC, as a consequence of anthropogenic greenhouse warming, was never assessed with a state-of-the-art climate model.

Professor Sybren Drijfhout from the University of Southampton said for a period of 20 years, the earth will cool instead of warm if global warming and a collapse of the AMOC occur simultaneously.

Thereafter, global warming continues as if the AMOC never collapsed, but with a globally averaged temperature offset of about 0.8 degrees Celsius.

"The 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 it takes more than a century before temperature is back to normal," Drijfhout said.

Interestingly, the effect of atmospheric cooling due to an AMOC collapse is associated with heat flow from the atmosphere into the ocean, which has been witnessed during the climate hiatus of the last 15 years.

"When a similar cooling or reduced heating is caused by volcanic eruptions or decreasing greenhouse emissions the heat flow is reversed from the ocean into the atmosphere. A similar reversal of energy flow is also visible at the top of the atmosphere," Drijfhout explained.

"These very different fingerprints in energy flow between atmospheric radiative forcing and internal ocean circulation processes make it possible to attribute the cause of a climate hiatus period," he added.

The study appeared in the journal Nature Scientific Reports.