The movie The Day After Tomorrow is loosely based on the theory of “abrupt climate change.” As a result of global warming, the Gulf Stream (part of the Atlantic thermohaline circulation) shuts down. The North Atlantic region starts to cool while heat builds up in the tropics. The result is a severe storm, the likes of which have never been seen, and a dramatic change in the global climate.
Do scientists agree about global warming?
Although scientists still argue about how fast and how much the atmosphere will warm, the mainstream scientific community agrees on three key points: the earth is warming; the warming is caused primarily by the build-up of GHGs (greenhouse gas) in the atmosphere; and that the warming will continue if we don’t reduce GHG emissions.
The Atlantic thermohaline circulation, which includes the Gulf Stream, acts like an oceanic conveyer belt that carries heat from the tropics to the North Atlantic region. Warm surface water from the tropics travels northward by the Gulf Stream. As the warm water cools in the North Atlantic, it sinks to the ocean floor, and then slowly moves southward until it returns once again to the tropics. This ocean circulation pattern is caused by differences in water temperature and salinity in the ocean.
Could climate change shut down the thermohaline circulation?
Global warming is expected to increase ocean temperatures and to increase the flow of freshwater into the ocean through precipitation, run-off, and melting of glaciers. A few models have projected a complete shutdown of the thermohaline circulation in the case of severe global warming, but this is being debated by the scientific community.
What are the chances of the thermohaline circulation shutting down?
We don’t yet know the probability of the thermohaline circulation shutting down. It depends on how much and how quickly the atmosphere warms. In general, it is considered possible but not very likely. If it were to occur, it would probably not happen within the next 100 years, and circulation would eventually recover, after decades or centuries
How can global warming cause cold weather?
Without the thermohaline circulation, not as much heat would be transported from the tropics to the North Atlantic region. We don’t know how much of this cooling would be balanced by the simultaneous warming in the atmosphere. While it is possible there would be cooling in the North Atlantic region, it is considered more likely that it would continue to warm, but more slowly than the rest of the world.
“This movement carries a tremendous amount of heat northward, and plays a vital role in maintaining the current climate,” Schlesinger said. “While shutting it down due to global warming would not cause an ice age, as was depicted in a recent blockbuster movie, ‘The Day After Tomorrow,’ eastern North America and western Europe would nevertheless experience a shift in climate.”