If AMOC goes out of control, life in the US and Europe will change dramatically.

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AMOC — This abbreviation means nothing to most people living on the East Coast of the United States, the Canadian coast, Greenland, Scandinavia, the United Kingdom, and Europe, but it is very important to them. AMOC stands for Atlantic Meridional Overturning Current, a vast river in the Atlantic Ocean that carries heat from the equator north along the east coast of the United States, then turns east at Cape Cod and Nova Scotia, heads toward the North Pole, and then west. . It follows the coast of Europe and descends towards the equator.

The AMOC is different from the Gulf Stream. To understand this, consider a traditional automobile cooling system. Coolant circulates throughout the engine, drawing heat away from the cylinders. It then travels to the radiator where it is cooled before returning to the engine where it is heated again. When the coolant flow stops, the engine gets hot and the radiator gets too cold. The car stopped moving and the driver was stranded on the side of the road.

A water pump attached to the engine circulates coolant through the car’s cooling system, but what moves the water in the AMOC? The simple answer is the equatorial trade winds and the Earth’s rotation. is. But there are other factors as well. Changes in seawater density and salinity are also important. Hot water is less dense than cold water, so ocean water that heats along the equator rises to the surface. Water with a lower salinity is also less dense and will float on top of water with a higher salinity.

dramatic climate change

From a research paper published in a journal on February 9, 2024 scientific progressThree Dutch oceanographers have warned that there are strong signs that the AMOC current is slowing down and could stop flowing completely in the not-too-distant future, perhaps within a few decades. What does that mean? According to AMOC’s model, London will experience an average 18°F cooler temperature and Bergen, Norway will experience a 27°F cooler temperature. Sea levels along North America’s east coast will rise significantly, negatively impacting cities and coastal communities in the region.

“We’re getting closer [to the collapse]But we don’t know how close we are,” Rene van Westen said. Associated Press. “We’re headed for a tipping point.” This study is the first to use complex simulations and include multiple components to track the strength of the entire important ocean circulation, and the study shows In other words, the cycle is slowing down.

The AMOC is a huge river that carries water at a rate of 30 million cubic meters per second, which is much more than all the world’s land rivers combined. In the tropics, the ocean surface is hotter and less dense, allowing it to ride on top of the cooler water below. Once it reaches Greenland or the North Pole, the water cools and becomes denser. It will also be more salty. The cold, heavy water forms an underwater waterfall that falls more than 4,000 meters to the ocean floor and begins its journey back toward the equator.

The problem is that global warming is dramatically increasing meltwater from the Greenland and Arctic ice sheets. All these freshwaters are less dense than AMOC water and interfere with normal circulation.

Could AMOC be shut down?

Is there a possibility that the flow of AMOC will stop? Yes, it is. In fact, it has happened many times throughout Earth’s history. This latest research suggests it could happen again within the next 100 years. The study breaks new ground in looking for red flags in salinity in the southern tip of the Atlantic between Cape Town and Buenos Aires. A computer model of the global climate simulated changes over 2,000 years and found that a gradual decline could lead to a sudden collapse in less than 100 years, with dire consequences.

The paper said the results provided a “clear answer” as to whether such sudden changes are possible. “This is bad news for the climate system and for humanity, because until now it was thought that the AMOC chip was just a theoretical concept and would disappear as soon as the complete climate system, including all additional feedbacks, was taken into account. “Van said.westin said guardian.

The researchers also mapped some of the effects of AMOC collapse. Sea levels in the Atlantic Ocean could rise by 1 meter in some areas, potentially flooding many coastal cities. The rainy and dry seasons in the Amazon could be reversed, pushing the already weakened rainforest past a tipping point. Temperatures around the world will fluctuate even more erratically. The southern hemisphere will be warmer. Europe will become dramatically colder and have less precipitation.While it may sound appealing when compared to current heating trends, the changes Attacks 10 times faster than today, making adaptation nearly impossible (emphasis added).

“What surprised us was the incidence of falls,” says lead author René van Westen of Utrecht University. “It would be catastrophic.” He said there isn’t enough data yet to tell whether this will happen next year or next century, but when it happens, the change will be He said it is irreversible on a time scale. Meanwhile, the direction of progress is definitely on the alarming side. “We’re moving toward that. It’s kind of scary,” Van Westen said. “We need to take climate change more seriously.”

A year ago, Danish researchers Peter and Suzanne Ditlefsen came to much the same conclusion as their Dutch colleagues. Using data provided by sensors in the North Atlantic, they said there is sufficient evidence that the AMOC could collapse as early as 2025 or as late as 2095. If that happens (and if it doesn’t), there will be severe disruption to the rain that billions of people depend on. Foods from India, South America, and West Africa. Europe will see an increase in storms and a drop in temperatures. That would lead to sea levels rising on the east coast of North America, further endangering both the Amazon rainforest and the Antarctic ice sheet. “I think we need to be very concerned,” Peter Ditlefsen said. “This is going to be a huge change. AMOC has not been closed for 12,000 people.”

This study was published in the journal Jul 25, 2023. nature communicationsused sea surface temperature data dating back to 1870 as a proxy for changes over time in the strength of the Gulf Stream, a component of the AMOC. They compared that date to the paths seen in systems approaching a particular type of intersection called a “saddle node bifurcation.” We would call it the “tipping point.”

Take-out

Is there takeout here? Of course there is, and you can write your own. A 2023 study by Andrew King and Stephen Sherwood at the University of New South Wales found that burning fossil fuels has added the equivalent of 25 billion atomic bombs of heat to the environment in the past 50 years alone. “Billions of nuclear bombs are used to produce 1.2 degrees Celsius of heat – what happens then?” the researchers ask. “That seems small when you consider daily temperature changes. But almost all of this energy so far has been absorbed by the oceans. No wonder our oceans are warming rapidly. there is no.”

Although we hear endless amounts of heartless ridicule from far-right leaders and media outlets about how fossil fuels have lifted millions of people out of poverty (because they hate poor people, this is Interesting), there is some truth to that. But at the same time, we have released energy stored over millions of years in a very short period of time. It’s like pouring pool water into a bathtub and being surprised when the bathtub overflows.

It’s really simple math. X plus 25 billion X is way too much by any measure. As anyone who graduated from high school can tell you, we’re still on a mad, never-ending quest for more coal, more methane, and more oil. If we continue our addiction to fossil fuels, we will degrade the only Earth we know to the point that humanity’s survival is threatened. Why are we so happy about that?