NEWS
- 25 March | The Honest UPSC Talk Nobody Tells You Click Here to see Abhijit Asokan AIR 234 talk →
- 10 March | SFG Folks! This dude got Rank 7 in CSE 2025 with SFG! →
- 10 March | SFG Folks! She failed prelims 3 times. Then cleared the exam in one go! Watch Now! →
News: As per a new study, the complete collapse of the Atlantic Meridional Overturning Circulation (AMOC) could lead to the release of large amounts of carbon into the atmosphere, turning it from a carbon sink into a source.
About Atlantic Meridional Overturning Circulation (AMOC)
- The AMOC is a system of ocean currents that circulates water within the Atlantic Ocean, bringing warm water north and cold water south.
- Mechanism: The circulation process begins as warm water near the surface moves toward the poles (such as the Gulf Stream in the North Atlantic), where it cools and forms sea ice.
- As this ice forms, salt is left behind in the ocean water. Due to the large amount of salt in the water, it becomes denser, sinks down, and is carried southwards in the depths below.
- Eventually, the water gets pulled back up towards the surface and warms up in a process called upwelling, completing the cycle.
- Importance of AMOC
- AMOC aids in distributing heat and energy around the earth (heat budget).
- Western Europe’s climate is less harsh even in winters because of AMOC (Gulf Stream, North Atlantic Drift).
- It acts as a carbon sink by absorbing and storing atmospheric carbon.
- Weakening of AMOC
- It takes an estimated 1,000 years for a parcel (any given cubic meter) of water to complete its journey along the belt.
- However, climate models suggest that the AMOC will weaken over the 21st Century as greenhouse gases increase.
- This is because as the atmosphere warms, the surface ocean beneath it retains more of its heat.
- Meanwhile increases in rainfall and ice melt mean it gets fresher too.
- All these changes make the ocean water lighter and so reduce the sinking in the ‘conveyor belt’, leading to a weaker AMOC.
- Consequences of a weakened AMOC
- A decrease in marine productivity in the North Atlantic (less sinking will lead to less mixing of water)
- More storms in Northern Europe
- Less Sahelian summer rainfall and South Asian summer rainfall
- A reduced number of tropical cyclones in the Atlantic
- An increase in regional sea level along the northeast coast of North America
