Although the movie The Day After Tomorrow is extreme but situation will not go far from it. This shutting down will cause a 7 degree Celsius temperature during wintertime and will change pattern of rainfall.

There was an inaccuracy to previous simulations. They said future climate change would not greatly affect the Atlantic circulation and that it would remain stable. But what left unsettled was how climate warms would affect the freshwater flow between Atlantic and Southern oceans.

This time Wei Liu and colleagues from Yale University set up an extreme climate scenario that would test the robustness of current. And the simulation showed that when carbon dioxide concentration is doubled in the atmosphere Atlantic current will be shuttered in 300 years.  But still the scenario is not realistic, as Science News reported.

Liu said that the next step is to use more realistic warming scenario to predict what the future will look like.

But Gerald Meehl, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo said that even with a more realistic scenario the applicability to the real world will be impeded by a lack of direct long-term observations of the Atlantic circulation.

According to Scientific American, the normal current movement is that the AMOC or Atlantic Meridional Overturning Circulation that serves as a colossal conveyor belt carries warm water from the South Atlantic going north along the surface of the ocean into the North Atlantic. The cold water sinks and flows southward into the South Atlantic when the current makes a U-turn near Greenland.

But this flow of current will change due to global warming, the researchers found that when AMOC slowed not enough freshwater from Atlantic flowed into the Southern ocean. This will decrease the saltiness of the Atlantic, weakened and finally will collapse the AMOC.