Do humans have the technology necessary to stop the Gulf Stream?

Question

Assume an evil dictator has taken over the whole continent of North America. He has the entire modern array of technologies at his disposal and plans to take over Europe. An evil plan comes into his mind — if Gulf Stream is stopped temporarily, it will be a lot easier to take over Europe as the most developed countries will freeze into death.

Is this a realistic plan or do humans lack the resources to cut such a massive ocean current?

Answer 1

Yes, we do have the resources, and we are already in the process of doing it.

By increasing greenhouse gas emissions, we are raising the global temperature. This will cause the polar ice caps of Earth to melt. When the northern polar cap melts, cold freshwater water will enter the more saline north-atlantic ocean and wreak havoc with the gulf stream system.

The real question is do we have the technology to prevent us from doing it?

Answer 2

Possibly. There are models suggesting that the climate change will affect the thermohaline circulation. But it is hard to come up with such a plan if one does not really believe in climate change.

Controlling something like this will be all but impossible.

Answer 3

From a technological perspective it is difficult to do.

The Gulf Stream carries 1.4 × 10^15J/sec heat flux (from the Atomic Rockets "Boom Table" http://www.projectrho.com/public_html/rocket/usefultables.php), while human civilization has an energy output of 1.5 × 10^13J/second in the year 2004.

So human civilization is outmatched by two orders of magnitude in terms of energy output by the Gulf Stream alone.

The second consideration is the Gulf Stream is powered by the rotation of the Earth and the heat energy delivered to the oceans by the Sun (both directly and indirectly through the atmospheric heat engine, the winds). The magnitude of these energies is even greater:

1.7 × 10^17J total energy from the Sun that strikes the face of the Earth each second

2.1 × 10^29J Earth's rotational energy (no time factor given)

While you could imagine some sort of gigantic dam or massive turbines trying to counter the flow of the Gulf Stream, you wold be essentially be pushing against a massive wall of moving water which would attempt to flow to areas of lower energy potential. You can imagine the consequences of that much energy and that mass of water being "bottled up", when the "dam" bursts the consequences will be catastrophic.

Of course technology isn't 100% efficient anyway, even the most optimistic plans to harvest the energy of the Gulf Stream using underwater turbines only suggests a range of 3-10 GW of energy can be extracted; only 1/3 of Florida's annual energy consumption.