Europe's freezing future? Ocean current slowdown raises alarm

The planet is facing a critical threat as scientists have long warned that the Atlantic Meridional Overturning Circulation (AMOC), a vital ocean current that moves heat and salt across the oceans, is slowing down. The current, also known as the thermohaline current, plays a vital role in redistributing heat, cold, and precipitation between tropical and northern Atlantic regions, which could have severe consequences. 

The AMOC helps balance heat, cold, and precipitation between the tropics and the northern Atlantic. If it collapses, it could trigger a sudden and catastrophic shift in the Earth's climate. This would not only affect global weather patterns but could paradoxically cause Europe to experience freezing temperatures despite the overall rise in global temperatures, as per the recent research from the University of Utrecht in the Netherlands, published in the journal 'Science'.

The study confirms earlier findings that the major ocean current has slowed considerably in recent decades, likely reaching its weakest point in the past millennium. Scientists caution that it is nearing a critical tipping point with potentially dire consequences.

According to voanews.com, a computer simulation suggests that a sudden shutdown of Atlantic Ocean currents could cause a deep freeze in large parts of Europe in the future. However, preventionweb.net says that climate change means that large-scale cold spells will become less frequent and less severe.

Disappearance of the Amazon

The AMOC carries warm water from the tropics to northern Europe. If it collapses, the northern hemisphere could experience sudden cooling, with temperatures in Europe potentially dropping by up to 15 degrees Celsius, and more than three degrees per decade. This could cause Arctic ice to extend much further south, simulations suggest.

Conversely, the southern hemisphere would see temperature increases, leading to drastic changes in global rainfall patterns and possibly even the disappearance of the Amazon, the world's largest tropical forest.

The study's authors caution that "no realistic adaptation measure can cope with such rapid temperature changes under an AMOC collapse."

The great ocean current acts like a conveyor belt that helps regulate the Earth's climate. It functions as a massive thermostat, rotating counterclockwise with its engine located off the coast of Greenland. However, as climate change causes ice to melt, increasing amounts of fresh water flow into this area, slowing the current.

In this system, the colder, deeper, and fresher water travels south, passing through the Americas, then east along the coasts of Africa. Meanwhile, saltier and warmer ocean water from the Pacific and Indian oceans moves north, rounds the southern tip of Africa, heads toward and around Florida, and continues up the east coast of the United States to Greenland. There, it cools, sinks, and the cycle begins anew.

The collapse, in 33 years?

The system of currents is why cities like Madrid and New York, despite being on the same latitude, have vastly different climates, and why Europe generally experiences milder winters than the United States.

As for when the AMOC might collapse, the authors of the latest study admit that current calculation methods and the uncertainties surrounding the future of climate change make it difficult to predict precisely. "We are getting closer (to collapse), but we are not sure how close. It is the million-dollar question, which unfortunately we cannot answer at the moment," says the study's lead author, Rene van Westen.

He emphasizes, however, that "we are heading toward a turning point." The timing of the collapse will depend on the rate of climate change driven by human activities, he adds.

According to the European Environment Agency (EEA), Europe is the fastest warming continent in the world, and climate risks threaten its energy, food security, ecosystems, infrastructure, water resources, financial stability, and people's health.

The EEA also says that snowfall is expected to decrease in central and southern Europe, but northern Europe may see mixed changes. Sea levels are expected to rise in all areas except the North Baltic Sea, and sea surface temperature is projected to increase in all European seas.

Other researchers have offered more specific forecasts. Contrasting with the 2021 assessments by the Intergovernmental Panel on Climate Change (IPCC), which deemed a total collapse of the AMOC unlikely this century, several studies now suggest that if current greenhouse gas emissions continue, the system could fail much sooner.

Utilizing advanced statistical tools and analyzing ocean temperature data from the past 150 years, Danish researchers estimated last year that the thermohaline circulation is likely to collapse between 2025 and 2095, with a 95% certainty. According to their calculations, the most probable year for the collapse is 2057, roughly 33 years from now.

Catastrophic consequences

The potential collapse of the AMOC could lead to catastrophic consequences. For instance, it could cause sea levels to rise along the North Atlantic coasts, threatening cities where hundreds of millions of people reside.

Additionally, it could alter global precipitation and drought patterns, lead to larger and more frequent heatwaves and other extreme weather events, and result in widespread shortages of water and food, along with severe economic impacts.

Most researchers draw their conclusions from early warning signals, which reveal instabilities in ocean currents. These signals are often seen as 'fingerprints' that indicate the strength of the AMOC, which has only been directly measured for the past 15 years.

Scientists in the Netherlands have developed an "observable, physics-based early warning signal" for the potential collapse of the AMOC. They identified that a significant reduction in freshwater transport at the South Atlantic boundary could indicate that the AMOC is approaching a critical inflection point.

The authors of the study are raising the alarm and urging global attention to the potential collapse of the AMOC. However, they emphasize an even more pressing priority: the immediate need to halt global warming. Their conclusion is clear: urgent, profound, and ambitious action is necessary to cease the emission of greenhouse gases worldwide. Without such measures, they warn, there may be no viable future.

Keep Reading

• Low price, bad wheat procurement process angers farmers in Bhopal
• PM Matsya Sampada Yojana falling short in Bhopal?
• Bundelkhand’s village realities & govt’s Jal Jeevan Mission data, do not match
• GR Interview: Extreme heat takes greater toll on Indian women

Follow Ground Report for Environmental News From India. Connect with us on Facebook, Twitter, Koo App, Instagram, Whatsapp and YouTube. Write us on [email protected] and subscribe our free newsletter. 

Don’t forget to check out our climate glossary, it helps in learning difficult environmental terms in simple language.