As scientist Dr. Broecker famously warned in the late 90's, “The climate system is an angry beast and we are poking it with sticks.” The beast seems to be rearing its head with an imminent threat of immediate and dramatic changes.
The Gulf Stream, originating in the Gulf of Mexico, is one of the world's strongest invisible rivers. It circulates enormous amounts of warm water northwards, up America and Canada's east coast, greatly influencing the world's temperatures. The currents from the Gulf Stream merge into the Atlantic Meridional Overturning Circulation, or AMOC, which then carry the warm water on to Europe and other northern regions.
Recent studies suggested that the currents in the Gulf Stream are weakening. Using deep water sensors in a network spread across the Atlantic Ocean, scientists have tracked these currents and their influence on the entire ocean. They found that a "cold blob" of ocean water has developed southeast of Greenland in recent years, possibly due to a weakening in the Gulf Stream's northward flow of warmer water.
If the Gulf Stream currents are indeed slowing, the effects could be disastrous. Changes could include a rise in sea levels on the east coast of the US, more powerful storms in the landlocked states, and decreased rainfall in Africa's already dry Sahel region. Furthermore, a weakening of the AMOC could cause Europe's temperatures to drop significantly.The Gulf Stream is among the mightiest rivers you will never see, carrying far more water than all the world’s freshwater rivers combined. Some scientists fear global warming is causing Atlantic currents to weaken. https://t.co/jaD7EiphpJ pic.twitter.com/g0IMoi1Mma
— The New York Times (@nytimes) March 3, 2021
“We’re all wishing it’s not true,” said Peter de Menocal, director of the Woods Hole Oceanographic Institution. The paleoceanographer fears “if that happens, it’s just a monstrous change.”
The AMOC system is driven by the sinking of denser water that cools with its contact to the atmosphere. As a result the lighter, warmer water is pulled to the surface and a current is generated. A change in water temperature and salinity could affect the "overturning" or sinking effect, in turn changing or weakening the currents.
Why is there a weakening in this flow? Scientists have set out to document sensor findings and better understand the cause behind these changes.
One theory suggested that global warming, which has melted glacier water in the Arctic, has infiltrated the Gulf Stream. The fresh water is lighter than salt water, and could affect the process of overturning. Other causes may include changes in wind patterns, greater rainfall, or even other interfering ocean currents.
Such a turning point, though difficult to predict, would bring vast changes within the next few years – and that is not something to take lightly.