For decades, oceanographers have been measuring the Atlantic Meridional Overturning Circulation (AMOC), a large system of ocean currents that greatly influences Earth’s climate. In recent years, data shows that it has weakened. But what does this mean?

“If this current system slows down significantly, it could negatively impact crop yields by changing weather patterns in the tropics,” said Spencer Jones, a visiting assistant professor in the oceanography department at Texas A&M University. Experts say AMOC is technically still within the natural normal speed range, but AMOC can become dangerously slow as global warming continues. Some scientists say we’re already seeing the effects of this slowdown in recent abnormal weather patterns. One thing most scientists agree on is the importance of AMOC for climate.

“Changes in the strength of the AMOC can change the weather in regions like Central America and Indonesia,” said Jones. “Although the atmosphere offsets some of the northward heat transport by AMOC, the Northern Hemisphere still gets slightly warmer than the Southern Hemisphere. Most scientists believe that temperatures in Northern Europe (especially Norway) are higher due to additional AMOK heat transfers. I agree that it is.”

Since the AMOC current is in its natural range, some may think it’s nothing to worry about. But Jones disagrees.

“While it is true that AMOC has been slowing for a long time, most scientists expect AMOC to slow down significantly over the next few decades,” Jones said. “This is because as the climate warms, the Greenland ice sheet melts and a great deal of fresh water enters the Labrador, Greenland and Irminger seas. Fresh water is lighter than salt water, so the surface waters in these areas will become lighter and less water will sink deeper into the ocean.”

While we don’t necessarily see all the work AMOC is doing to keep the climate stable, Jones notes that its currents absorb excess carbon dioxide as well as excess heat.

“About 40 percent of the additional carbon dioxide and 90 percent of the heat that humans add to the Earth system by burning fossil fuels is dissolved in the surface ocean,” Jones said. “But the surface ocean can only absorb a limited amount of carbon dioxide and heat. AMOC transports this surface water to the deep ocean, allowing the ocean to absorb more carbon dioxide and heat, and the temperature of the atmosphere decreases. If AMOC slows, less carbon dioxide and heat will be absorbed by the deep ocean and more enter the atmosphere. will lead to higher surface temperatures.”

Climate change itself will have negative consequences. Jones said there could be effects of drought stress on agricultural production that could lead to food insecurity on a global scale.

“Because of its importance for the Intertropical Convergence Zone, a slowdown in AMOC will lead to large changes in precipitation in the tropics, including Central and South America, India, Southeast Asia and parts of Africa,” Jones added. “Billions of people depend on the crops grown in these regions, and changes in precipitation patterns can make it more difficult for these people to find food, leading to mass starvation and mass migration.”

According to Ramalingam Saravanan, professor and head of the Department of Atmospheric Sciences, global warming may be the cause of the AMOC slowdown.

“One of the reasons for its slowdown may be global warming, which can increase precipitation in the north Atlantic regions, for example, making the water fresher and lighter,” Saravanan said. Said. “One way to stop this is to stop global warming.”

Fortunately for policymakers, there are many strategies to prevent flows from falling to dangerously low levels, such as ending the burning of fossil fuels and reducing emissions of carbon dioxide and other greenhouse gases.

“Whatever we do to reduce global warming, we will need to make changes in a wide variety of factors, including how we operate public transport and the electrification of the infrastructure we have,” Jones said. Said. “We need to think about how to reduce the number of flights and replace them with electric trains. We can start to stop eating so much red meat in the agriculture sector. Consuming less beef, in particular, is one of the easiest ways to reduce emissions because land use causes greenhouse gas emissions. “We have to start cooling. We can start using electricity, wind, solar, and by installing infrastructures like heat pumps, we can reduce the amount of energy we use to do that.”

Jones said many experts believe that slowing the AMOC and other major changes in the Earth’s environment and climate could be prevented if policymakers around the world make a concerted effort to stop global warming.

“Individual action is important, but it’s more important that everyone agrees to support programs that help us move towards exciting services and increasing public transport, because really, not many people have the ability to drastically reduce their carbon footprint without help.” Jones.