Will ocean currents collapse? Atlantic ‘cold blob’ study offers clues
Researchers at the University of California, Riverside, have linked a cooling region south of Greenland, known as the “cold blob,” to a slowdown in the Atlantic Meridional Overturning Circulation (AMOC). This oceanic conveyor belt distributes global heat, and its weakening could alter weather patterns and raise sea levels along the U.S. East Coast.
A recent study led by Wei Liu, a climate scientist at the University of California, Riverside, found the area has cooled by up to 1 degree Celsius (1.8 degrees Fahrenheit) over the last few decades. Liu stated the region south of Greenland is highly sensitive to AMOC changes, noting that surface cooling from a slowdown may exceed background greenhouse gas warming.
Why is the North Atlantic “cold blob” forming?
The cooling is tied to the AMOC, a complex network of ocean currents that functions as a global conveyor belt. According to the National Oceanic and Atmospheric Administration (NOAA), these deeper currents are driven by variations in salinity and temperature.
Kai-Yuan Li, a PhD candidate at UC Riverside, described the “North Atlantic Warming Hole” as one of the most striking features of modern climate change. While most of the global ocean has warmed, this specific region has shown long-term cooling, according to NASA’s Goddard Institute for Space Studies.
How could a weakening AMOC impact global business and infrastructure?
Because these currents carry heat across the planet, changes may create a domino effect. The strongest impacts could be felt in northern Europe, Iceland, and Greenland, where cooler ocean temperatures may alter air temperatures and shift pressure systems and storm paths.
Marine ecosystems may also adjust as salinity and temperature patterns evolve. Furthermore, several studies indicate that sea levels along the U.S. East Coast would likely rise faster if the AMOC continues to weaken.
What happens if the ocean currents shut down?
Scientists caution that ocean currents are weakening and may eventually become too weak to distribute heat globally. If any part of the AMOC slows, it could potentially bring the entire system to a standstill.
Researchers estimate the system will weaken by at least 20% by 2100. In a more extreme scenario, the AMOC may eventually shut down completely.
Frequently Asked Questions
What is the North Atlantic Cold Blob?
It is a region south of Greenland that has cooled by up to 1 degree Celsius (1.8 degrees Fahrenheit) over several decades while most other global ocean areas have warmed.
How does the AMOC affect the U.S. East Coast?
According to Carbon Brief and a 2015 Nature study, a slowdown in the AMOC is linked to faster sea level rise, such as the 128 millimeter increase seen north of New York City between 2009 and 2010.
What are the long-term projections for the AMOC?
Scientists estimate the AMOC will weaken by at least 20% by the year 2100 and it may eventually shut down completely.
How should coastal cities prepare for the potential of accelerated sea level rise linked to ocean current changes?