THE EFFECTS OF SLOWING OCEAN CURRENTS

Author: Ellie Wang

Editors: Shirley Chen and Max Ye

Artist: Gianluca Zhang

Climate change has caused many adverse changes to the environment around the globe, and a notable portion of those changes has affected the ocean in particular. One seemingly trivial issue is the gradual slowing of ocean currents around the globe In the face of more obvious problems like global warming and plastic pollution, how do slowing currents measure up?

First, here is some background information on how these currents work. A phenomenon known as thermohaline circulation drives the movement of global ocean currents. Although winds drive currents within the ocean’s upper 100 meters of water, they can’t reach the ocean currents thousands of meters below the surface

That’s where thermohaline circulation has its influence. The components of the word “thermohaline” “thermo” meaning temperature and “haline” meaning salinity indicate the two environmental conditions that cause this type of circulation As water near the polar regions cools and becomes sea ice, this increases the concentration of salt in the water, which in turn increases the density of that water. Denser water sinks to the ocean floor, pulling in surface water to replace it, which also becomes cold and salty enough to sink. This positive feedback loop is where the global conveyor belt starts, which occurs near Greenland. However, the strength of thermohaline circulation weakening by the rising temperatures caused by climate change

Global warming causes sea ice to melt, which decreases the salt concentration in the polar regions. Thus, the rate at which the water is sinking and creating currents is continually decreasing as global warming worsens According to current findings, the global conveyor belt is in danger of completely collapsing if these conditions continue What would the consequences of a complete stop be? Unfortunately, some effects of the weakening currents can already be identified. One signicant part of this global conveyor belt is the Atlantic Meridional Overturning Circulation (AMOC), or the portion owing within the Atlantic Ocean The surface part of the AMOC in the northwestern Atlantic is the Gulf Stream, which is essential for regulating the climate in the southeastern United States and Europe. The Gulf Stream’s warm waters cool Florida’s summers and warm its winters, in addition to bringing warmth to Europe. Since the global conveyor belt has been stalling, a pileup of warm water is gathered at the beginning of the Gulf Stream, contributing to hotter temperatures in the southeastern United States and colder temperatures in Europe and parts of North America. This temperature shift can also disrupt climate conditions in these areas In other places around the globe, such as India, the slowing currents are also preventing adequate cooling, leading to sea level rises, increasing the probability of deadly heat waves, and possibly altering the monsoon cycle. Farmers in India and other parts of the world rely on the monsoon cycle’s periodic heavy rainfall. Without it, the agriculture industry in these areas could be negatively impacted

The slowing global conveyor belt threatens vulnerable populations, which includes people with health conditions and nancial insecurities. The importance of this global ocean circulation is another reason why we should put more effort into combating climate change and global warming.