The Gulf Stream & Climate Change

The ocean conveyor belt and
the Gulf Stream.

Ocean currents have a direct
influence on our lives.

They determine our weather, our
climate, and much more.

The ocean currents and wind systems

transport heat from the equator
to the poles

and operate like a large engine
for the global climate.

In the oceans, there are numerous
currents.

The so-called ocean conveyor belt
is very important for our climate.

This term describes a combination
of currents

that result in four of the five global
oceans exchanging water with each other.

They form a worldwide circulation system.

The conveyor belt is also called the
thermohaline circulation,

with “thermo” referring to
the temperature,

and “haline” to the salt content
of the water.

Both determine the density of the water.

While the masses of water may be
moved in part by wind,

primarily the different densities
of the global oceans are

responsible for their movement.

Warm water has a lower density and rises
while cold water sinks.

The water’s density also increases with
a higher salt content.

At the equator the heat from the
sun is especially strong,

resulting in a lot of evaporation and
thus a rise in the water’s salt content.

That is where the Gulf Stream begins.

The Gulf Stream is very important
for the European climate.

Its length of 10,000 km makes it one of
the largest and fastest currents on Earth,

and it’s very warm.

At roughly 2 m/s it brings up to
100,000,000 m³ of water per second

towards Europe.

A constantly blowing wind, the
southeast trade wind,

drives warm surface water to
the northwest, into the

Gulf of Mexico, where it heats up
to 30 °C.

The turning of the Earth and the
west winds then direct

the Gulf Stream towards Europe
and split it up.

One part flows south, another east
to the Canary Current,

and a third part flows north where
it releases a lot of heat

into the atmosphere as the
North Atlantic Current.

The water becomes colder there.

Its salt content and density rise on
the account of evaporation

and it drops down between
Greenland, Norway, and Iceland.

There we also find the largest
waterfall on Earth.

The so-called Chimneys, roughly 15-km-wide
pillars with water falling up to 4,000 m.

17,000,000 m³ of water per second, or
roughly 15 times more water than

is carried by all the rivers in the world.

This creates a strong maelstrom, which
constantly pulls in new water

and is the reason that the Gulf Stream
moves towards Europe.

Countless species use the Gulf Stream as a
means of transport on their trips

from the Caribbean to northern areas.

But it doesn’t just bring us animals;

an enormous quantity of warm air also
comes with it.

In order to produce the same heat that it
brings to the shores of Europe,

we would need 1,000,000 nuclear
power plants.

That’s why we also call the Gulf Stream
a heat pump.

Without it, the temperature would
be significantly colder here,

at least five to ten degrees.

Instead of lush fields, we would have
long winters and sparse ice-covered

landscapes in Europe.

In the last few years, scientists and
pundits in the media have repeatedly

expressed the fear that the Gulf Stream
could come to a standstill

due to climate change.

Because if the polar caps actually melt,
the salt content in the water

off Greenland would fall, as would
its density.

The North Atlantic Current would no longer
be heavy enough,

and so it woundn’t sink as usual.

In the worst case, that would bring the
Gulf Stream, our heat pump, to a stop.

Some climate experts also assume that
climate change could

compensate for this effect.

We know that it can be normal for the
climate to change

by looking at the development of the Earth
over the last few million years.

There are ice ages and warm periods.

In the last ice age, a gigantic flood of
melting water crippled

the heat-bringing North Atlantic Current,
covering the northern hemisphere in ice.

Scientists have different views on the
impact that climate change will have

on the global ocean conveyor belt, but
one thing is clear:

when the climate changes, then the complex
system of ocean currents and winds,

which has remained fairly stable since the
last ice age,

will change in ways that we don’t
yet understand.