Due to global warming, the deep ocean current around Antarctica that has been relatively stable for thousands of years could be heading for a “collapse” over the next few decades.
Such a sudden shift could affect the planet’s climate and marine ecosystems for centuries to come.
So says A A recent study It has been published in the peer-reviewed journal Nature.
Cold water plunging near Antarctica drives the deepest flow of a network of currents that stretch across the world’s oceans, known as the overturned circulation. Solstice carries heat, carbon, oxygen and nutrients around the world.
This, in turn, affects climate, sea level, and the productivity of marine ecosystems. In fact, the loss of nutrient-rich seawater near the surface could harm fisheries, according to the study.
“on the verge of collapse”
This deep-ocean current has remained relatively stable for thousands of years, but as greenhouse gas emissions increase and Antarctic ice melts, the Antarctic upturn is expected to slow dramatically over the next few decades.
“Our models show that if global carbon emissions continue at the current rate, the Antarctic reversal will slow by more than 40% in the next 30 years – and on a trajectory that appears to be heading for collapse,” said the study’s lead author. Matthew England from the University of New South Wales in Australia.
Speaking about the new research, paleoclimatologist Alan Meeks told Reuters, “It’s amazing to see it happen so quickly.” “It looks like it’s starting to work right now. That’s major news,” added Meeks, a paleoclimatologist at Oregon State University and co-author of the IPCC’s latest assessments, who was not involved in the study.
“Unknown Levels”:The National Oceanic and Atmospheric Administration (NOAA) says the gases that fuel climate change are still rising at an alarming rate.
The Atlantic Current was also affected
Such a collapse would also affect the nearby Atlantic Ocean current, known as the Atlantic Meridian Overturning Circulation, or AMOC, which transports warm, salty water from the tropics north at the ocean surface and cooler water south at the ocean floor.
This current includes the well-known Gulf Stream, which affects weather patterns in the United States and Europe. “The main problem for the AMOC right now is meltwater from Greenland, which is slowing that stream down,” England told USA TODAY.
Other studies in recent years about AMOC have drawn comparisons to the scientifically inaccurate 2004 disaster film “The Day After Tomorrow”, which used a stopping ocean current as a premise for the film. In a 2018 study, the authors said a crash was at least decades away but would be a disaster.
the day after tomorrow?:Study warns of ‘irreversible transition’ in ocean currents that could quickly freeze parts of North America
The reason for the current slowdown
What causes the currents to slow and possibly collapse? England wrote that “climate change is the cause.” Conversation. “As Antarctica melts, more fresh water flows into the oceans. This disrupts the sinking of cold, salty, oxygen-rich waters to the ocean floor.”
Specifically, more than 250 trillion tons of that cold, salty, oxygen-rich water near Antarctica drown each year. This water then spreads northward, carrying oxygen to the depths of the Indian, Pacific, and Atlantic oceans.
England said: “If the oceans had lungs, this would be one of them.”
“Simply put, a slowdown or collapse of the fluctuating circulation would alter our climate and marine environment in profound and potentially irreversible ways.” he wrote.
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How will it affect the United States?
England told USA TODAY that the main impact for North America would be sea level rise along the east coast.
In addition, another impact of Amok’s collapse would be the transition to a La Nina-like country in the Pacific Ocean, England said. La Niña, a natural cooling of sea water in the tropical Pacific Ocean, affects weather and climate in the United States and around the world.
Droughts and wildfires tend to be worse in the southwestern United States, and more hurricanes in the Atlantic Ocean.
What can he do?
England wrote in the conversation: “Our study shows that not only will continued ice melt raise sea levels, but it will also alter massive upturn currents that could lead to more ice melt and thus sea level rise, damaging climate and ecosystems around the world.” “. “It’s another reason to tackle the climate crisis — and fast.”
Contributing: The Associated Press