Major Atlantic Ocean current could collapse much sooner than expected
A new study, published in Nature Communications, warns that a key ocean current system in the Atlantic Ocean could be headed for a collapse and that too as soon as 2025. This comes at a time when heat records in the Atlantic have themselves been broken. Also, the study's estimates are much sooner than what former models have predicted so far.
AMOC regulates heat from the tropics to the northern hemisphere
The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in global climate. These currents regulate ocean heat from the tropics to the northern hemisphere. However, the AMOC has been slowing down due to climate change. The study points out that the collapse of AMOC is worrying as it's considered to be one of the most important tipping elements in Earth's climate system.
What impact would AMOC's collapse have?
If as predicted, the vast AMOC ocean current system does collapse, it would have serious implications on climate patterns. For one, the tropical regions will see haphazard monsoons. Europe and North America will be subjected to extreme winters. On a broader scale, these disturbances would further go on to have an impact on ecosystems, posing a threat to food production and food safety.
A decline in AMOC has been observed between 2004-2012
AMOC has been directly observed only since 2004, which does not exactly provide a full picture of the slowing trajectory of the ocean current. "Over the period 2004-2012, a decline in the AMOC has been observed, but longer records are necessary to assess the significance," states the study. Their work involved identifying an ocean area where surface temperatures correlated the best with circulation conditions.
AMOC could collapse as soon as 2025
Researchers made the estimations on AMOC based on "early-warning signals, primarily an increase in variance (loss of resilience) and increased autocorrelation (critical slowing down)," This led them to conclude AMOC could collapse as soon as 2025 and no later than 2095.
The study's estimates are worryingly sooner than those of IPCC
What's worrying is that the study's estimates are sooner than those suggested by the Intergovernmental Panel on Climate Change (IPCC) which says a "full collapse is unlikely within the 21st century." However, the paper highlights those models have "biases toward overestimated stability of the AMOC, both from tuning to the historic climate record, poor representation of the deep water formation, salinity, and glacial runoff."
Increasing greenhouse emissions are exacerbating the situation
Another factor researchers are concerned about is the speed at which we are heading toward the collapse of AMOC. What's not helping the situation is the increasing amount of global greenhouse emissions. The study emphasizes the need for "fast and effective measures" to curb emissions if we intend to stall the imminent destabilization of the important ocean current system.
