The warm ocean currents flowing from the Gulf of Mexico across the Atlantic Ocean to Europe are gradually weakening, resulting in insufficient heat supply for the northern regions. This change will lead to a colder climate in Europe within just a few decades.
This observation and prediction have been made by scientists at the UK’s National Oceanography Centre (NOC).
After originating in the Caribbean Sea, the warm ocean current from the Gulf of Mexico splits into two as it flows across the Atlantic towards Europe: one branch moves northeast towards Europe, while the other circulates back into the Atlantic Ocean (see the diagram).
During its journey, the northeastern branch of the current releases a significant amount of heat into the atmosphere, providing a warm climate for the European mainland.
“The heat released by this current is equivalent to the heat output of one million power plants,” says scientist Harry Bryden from NOC.
As the current moves to the northern latitudes near Greenland and Iceland, the water cools down, causing it to sink to the ocean floor. This transformation process is known as “overturning”.
Afterward, the cold water flows southward. Similar to a closed conveyor belt, the warm water circulates on the ocean surface northward, while the cold water flows back at depths of hundreds or thousands of meters below the surface.
According to NOC’s research, the activity of these cold currents has changed significantly over the past half-century. Bryden states, “We found that the southward flow of cold water has decreased by 30% compared to before. In 2004, there was a higher volume of flow into the Atlantic Ocean and fewer instances of overturning. As a result, the heat supply to Europe has diminished.”
Climate monitoring centers regularly predict that the ocean currents in the North Atlantic could significantly weaken or even disappear entirely. This phenomenon occurs as Arctic ice melts and Arctic rivers flow more rapidly, leading to a substantial decrease in salinity in the northern seas. A reduction in salinity means that the water density decreases, preventing the currents from sinking and weakening their activity.
According to climate centers’ predictions, if these currents were to disappear completely, Europe could experience a temperature drop of 4 to 6 degrees Celsius.
Bryden adds, “If this happens, we will witness temperature changes at northern latitudes. The heat that was previously supplied to Europe will revert to the tropical Atlantic regions, significantly impacting the climate systems in Africa, the Mediterranean, and Central America.”
