The Day After the Decade After Tomorrow
The movie The Day After Tomorrow saw the planet globally affected by the cessation of the ocean conveyor belt, or, more precisely known as the thermohaline circulation (THC). The northern hemisphere suffered massive drops in temperature, rises in sea level and a variety of other climate conditions.
Putting aside the fantastical nature of the speed with which this happened, the base science is sound; that an increase in freshwater could slow or shutdown the thermohaline circulation, causing an unexpected and unhelpful ice age.
