While climate disasters and record-high temperatures have brought climate change to the everyday experience of most humans, for a long time, “global warming,” has invoked mental images of shrinking ice caps and desperate polar bears.
And the Arctic is indeed warming rapidly — at three to four times the global average.
With that in mind, new research out of the University of California, Riverside suggests the slowing of a key ocean current could help reduce projected warming by up to 2 degrees Celsius.
The study looked into the effects of slowing the Atlantic Meridional Overturning Circulation, or AMOC. This current transports heat from the tropics to higher latitudes, and slowing it down could provide some relief to the Arctic.
“The AMOC is a critical component of our climate system because it moves heat around the globe,” said Yu-Chi Lee, UCR graduate student and first author of the study. “We found that its weakening reduces the amount of heat reaching the Arctic, which slows down the rate of warming.”
Temperatures in the Arctic are predicted to rise by a devastating 10 degrees Celsius by the end of the century, but the new study shows that slowing the AMOC current could mean that temperatures will only rise by 8 degrees Celsius.
What’s the nuance?
Of course, a rise in temperature by 8 degrees is still incredibly severe. Slowing ocean currents alone will not save us.
As sea ice melts, animals (like polar bears) face habitat loss. Additionally, as sea ice disappears, water absorbs more sunlight and causes even more warming.
As Wei Liu, UC Riverside associate professor of climate change and co-author of this research puts it: “The AMOC slowdown may offer some temporary relief in the Arctic, but this is not a simple good-news story.”
Additionally, the AMOC slowdown may reduce warming, but it may also cause other disruptions to the climate system, including a potential shift in the Intertropical Convergence Zone, a tropical rain belt.
If this zone moves more southward due to the slowdown, more areas could experience droughts, which would also impact agriculture and water supply — especially in Africa.
“The overall impact on ecosystems and weather patterns, both in the Arctic and globally, could still be severe,” Lui said.
The research team used a coupled climate model, which factors in interactions between the ocean, atmosphere, land, and sea ice, to run simulations on future Arctic warming.
Their two simulations included one that allowed the AMOC to slow “under the influence of rising greenhouse gasses,” and another that artificially maintained the current’s strengths.
The simulations pointed to how significantly Arctic warming is tied to the AMOC slowdown, though it also positions scientists to better understand the big picture.
“While the AMOC slowdown might provide some short-term benefits, its broader impacts show us that even small shifts in ocean circulation can cause ripple effects across the planet,” Lee said.
While a slowing AMOC current could reduce some of the most devastating impacts of a warming planet, it is also an indication that more work must be done to reverse (or capture) emissions.
The scientists hope that their latest research provides a new benchmark to help curb the impacts of climate change before it’s too late.
“Climate change is far from a one-region issue,” Lee added. “The future of the Arctic — and the world — depends on how we respond today.”
Header image courtesy of AWeith (CC BY-SA 4.0)
