Climate scientists warned in a terrifying new paper that was published in Nature Climate Change on Thursday that the Atlantic Meridional Overturning Circulation (AMOC) – more commonly known as the Gulf Stream – has reached its slowest speeds in 1,000 years and could be close to reaching a tipping point of total collapse.
“Observations and recently suggested fingerprints of AMOC variability indicate a gradual weakening during the last decades, but estimates of the critical transition point remain uncertain,” the report’s abstract states. “Significant early-warning signals are found in eight independent AMOC indices, based on observational sea-surface temperature and salinity data from across the Atlantic Ocean basin. These results reveal spatially consistent empirical evidence that, in the course of the last century, the AMOC may have evolved from relatively stable conditions to a point close to a critical transition.”
By analyzing ice core samples collected from the last 100,000 years and historic records of sea surface temperatures and oceanic salinity levels, researchers at the Potsdam Institute for Climate Impact Research in Germany found “an almost complete loss of stability over the last century,” meaning the Gulf Stream is likely heading for a full shutdown, although when that may occur remains unclear.
“The signs of destabilization being visible already is something that I wouldn’t have expected and that I find scary,” said Doctor Niklas Boers, one of the study’s authors, as reported by The Guardian. “It’s something you just can’t [allow to] happen.”
He added that “the findings support the assessment that the AMOC decline is not just a fluctuation or a linear response to increasing temperatures but likely means the approaching of a critical threshold beyond which the circulation system could collapse.”
It is also unknown how what quantity of carbon dioxide is required to saturate the atmosphere in order to trigger such a cataclysmic event, however, Boers stressed the importance of drastically reducing carbon emissions to avoid the unthinkable.
“So the only thing to do is keep emissions as low as possible. The likelihood of this extremely high-impact event happening increases with every gram of CO2 that we put into the atmosphere,” Boers said.
The AMOC functions on a delicate balance of cold, hot, fresh, and salt waters. Variations in their densities combined with the inertia of each fluid cause them to mix and form currents that drive warm tropical water northward, similar to how gases interact in the atmosphere.
That natural geophysical rhythm is responsible for stabilizing the climate in Earth’s Western Hemisphere.
But rapidly warming seas along with the accelerated melting of Arctic and Antarctic glaciers are dumping trillions of gallons of freshwater into the Atlantic and diluting its salinity levels. The growing concentration of atmospheric carbon dioxide – 75 percent of which is absorbed by seawater – is acidifying the oceans and causing temperatures to climb.
These feedback loops are undoubtedly a result of human activity and are throwing off the crucial equilibrium upon which a stable climate depends.
If the AMOC were to slow down significantly – or worse, stall – the consequences would be devastating and hellish on a global scale and would unfold relatively quickly.
They include “severely disrupting the rains that billions of people depend on for food in India, South America, and West Africa; increasing storms and lowering temperatures in Europe; and pushing up the sea level in eastern North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets,” noted The Guardian.
Unfortunately for us and much of the life on Earth, the planet is careening towards numerous critical tipping points – simultaneously – which scientists have for decades warned are irreversible and unstoppable. In other words, our civilization is running out of time to prevent a planetary cataclysm of unprecedented and unimaginable proportions.
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Brandon is a political writer for the Hill Reporter specializing in current events, breaking news, and scientific discovery. Brandon holds a Bachelor of Music degree from Indiana University. He lives in New York City.