Climate change could stop vital ocean current, study finds

Man-made global warming threatens to collapse a system of currents in the Atlantic Ocean that regulates and impacts weather across the world, according to a new scientific study.

The Atlantic Meridional Reversal Circulation, or AMOC, a section of the Gulf Stream, carries warm water from the tropics to the north and cold water from the North Atlantic to the south.

This natural redistribution of heat has long worked to stabilize regional climatic and meteorological conditions; however, scientists have warned that the system is slowing down. A 2019 United Nations report concluded that while the power is “very likely” to weaken this century, a blackout was unlikely.

But the new study, published Thursday in the journal Nature Climate Change, indicates that the situation could be much more serious than previously thought. The current changes may be linked to “an almost complete loss of stability in AMOC over the past century,” the analysis says.

“The results support the assessment that the decline in AMOC is not just a fluctuation or linear response to increasing temperatures, but likely signifies approaching a critical threshold beyond which the system traffic could collapse, ”Niklas Boers, a researcher at the Potsdam Institute for Climate Impact Research in Germany and the study’s author, said in a statement.

A crippled Atlantic Current system could trigger catastrophic and potentially irreversible changes, ranging from rising seas in North America to major disruption of seasonal monsoon rains in Asia and South America.

“The mere possibility that the AMOC tipping point is near should be enough motivation for us to take countermeasures,” Levke Caesar, climate physicist at Maynooth University of Ireland, told the Washington Post. “The consequences of a collapse would likely be far-reaching.”

But Andreas Schmittner, a climatologist at Oregon State University, is skeptical of the study’s conclusion.

“The method used in the article was developed and tested in very simple models of dynamic systems, but it is then applied to observations of sea surface temperatures and salinities,” he told HuffPost in an email. “I think their method is brand new and needs to be tested by different investigators and explored further in complex climate models to see if it works with the data they used. I think it is premature to conclude that AMOC is on the verge of collapse.

The study precedes a major report by the United Nations Intergovernmental Panel on Climate Change, or IPCC, the main consortium of researchers studying the rise in temperature caused by humans. The assessment, scheduled for August 9 and written by more than 200 scientists, will provide an up-to-date understanding of the crisis and its current and future effects around the world.

There is no way to determine the level of greenhouse gas emissions that would cause AMOC to collapse altogether, Boers told The Guardian. “The only thing to do,” he said, “is to keep the emissions as low as possible. The likelihood of this extremely high impact event occurring increases with every gram of CO2 we release into the atmosphere. “