Debunking headlines such as "The Gulf Stream could collapse in 2025"

Rather than using the accurate but complex term "Atlantic Meridional Circulation", journalists opt for the widely recognised "Gulf Stream". This simplifies the news for the average reader, who may not understand the details of Atlantic hydrology but is likely to be familiar with the Gulf Stream and know that its disappearance would indeed be alarming. People have become more aware of the importance of climate change. But is it acceptable to distort facts if it serves a noble cause?

28 August 2023

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Instead of employing the precise but complex term “Atlantic Meridional Circulation,” journalists opt for the widely recognized “Gulf Stream.” This way, they simplify the news for the average reader, who may not understand the details of Atlantic hydrology but is likely familiar with the Gulf Stream and knows that the disappearance of the Gulf Stream would indeed be alarming.

The intended outcome has been achieved: people have become more aware of the significance of climate change. Nevertheless, it’s still a lie. Is it acceptable to distort facts if it serves a noble cause?

Presenting breaking news that elicits basic emotions exploits our tendency to perceive the world in terms of right and wrong. Yet, this oversimplifies matters (excluding situations like the war between russia and Ukraine), as the world is filled with various shades of grey, making it impossible to hit solely on a single emotion. In adopting such tactics, the media undermines the importance of the news itself, concealing it like a piece of candy in a cheap wrapper of misleading information regarding its contents.

What is this all about?

In recent weeks, certain media outlets have featured articles with sensationalist headlines, such as “The Gulf Stream could collapse in 2025.” The Guardian, Live Science, and the NY Post have all engaged in this practice.

Unfortunately, Live Science was referenced by Ukrainian sources like Babel and Hromadske. This serves as a clear example of what can be likened to the children’s game of “broken telephone,” albeit with adult media resources instead of kindergarten children.

However, the Gulf Stream will not collapse in 2025. As long as the wind continues to blow, and the Earth rotates, the Gulf Stream will persist [1]. The study published in Nature Communications [2], which triggered the misleading headlines, actually pertains to the Atlantic Meridional Overturning Circulation (AMOC) and not the Gulf Stream itself. In fact, the article in question doesn’t mention the Gulf Stream at all.

~90% of the Gulf Stream currents are unrelated to the AMOC system; they are connected only to the North Atlantic Current. This current represents a minor offshoot of the Gulf Stream, directing its flow towards the Greenland and Norwegian Seas. The Gulf Stream itself carries 150 sverdrups of water (1 sverdrup = 1 million cubic metres of water per second), while the AMOC conveys 15 sverdrups, equivalent to ~10% of total Gulf Stream water [3].

The Gulf Stream’s near-surface current is primarily propelled by winds, a phenomenon unaffected by climate variations. To impede this current, one would need to halt the planet’s rotation. The deep AMOC operates by sinking far beneath the surface within the cold and saline waters of the Greenland and Norwegian Seas, something like a conveyor belt. This subterranean flow, which is cold and slow, requiring roughly 1,000 years to complete a full cycle, is directed southward, towards the Southern Ocean. When the water becomes less saline, influenced by precipitation and glacial melting, and warms up, this movement slows down. Consequently, warm water remains in place, the flow halts, and the transfer of heat from the southern hemisphere to the northern hemisphere diminishes.

This particular concern has preoccupied climate scientists for many years. The Atlantic Meridional Overturning Circulation (AMOC) is very important in shaping the climate, particularly in the Northern Atlantic region. Research efforts are underway to forecast potential future scenarios, involving the creation of various models aimed at reconstructing the AMOC system across different time frames.

In one of its reports, the Intergovernmental Panel on Climate Change (IPCC) reached the following conclusion: “In the 21st century, the AMOC is projected to weaken, although a collapse is highly improbable. Up to 2300, collapse is unlikely under the high emissions scenario, and extremely unlikely under the low emissions scenario” [4].

Regarding the Gulf Stream, the IPCC has stated that, based on theoretical understanding, the complete disintegration of the AMOC would not result in the disappearance of this ocean current. It’s essential to understand this story, as a number of diverse studies employ various models, calculations, and simplifications. For instance, some studies consider the impact of Greenland’s ice melting, while others do not. Accounting for all influencing factors is nearly impossible, leading to varying forecasts as some forecasts give a higher probability of certain changes in the AMOC, and others - lower.

The AMOC’s future behavior remains uncertain. It could potentially transition to a different mode, alter the location of water immersion, or maybe a tipping point of some kind will actually occur in the centuries to come, or it might not change at all. This intricate system of currents is considerably complex, with its performance varying across distinct latitudes. Consequently, it would be wrong to draw affirmative conclusions from a single study.

In their publication in Nature Communications, Danish scientists write about changes within a 95% confidence interval spanning from 2025 to 2095. In July of this year, experts in climate and ocean science convened to deliberate AMOC observations and research. Professor Eleanor Frajka-Williams noted, “Most participants concluded that we do not possess a clear understanding of how the AMOC will react to future anthropogenic alterations” [5].

The moral of the story is that scientific research is incredibly complex, demanding days or even weeks of dedicated study to comprehend a specific topic fully. Can journalists, who disseminate news with the swiftness of the Gulf Stream, afford such time? Highly improbable. As demonstrated, there are instances where merely accessing a source or distinguishing between the Gulf Stream and AMOC proves challenging. That’s worth remembering when reading what has been written about a research study or retold narratives.

Authored by Dmytro Filipchuk. For further information into the factors influencing the Gulf Stream’s movement, refer to the video available on the channel of German scientist Sabine Gossenfelder [6].

References:

#BehindtheScience