Atlantic Meridional Overturning Circulation shows localized slowdowns, signaling broader oceanic destabilization with global climate implications

Indigenous coastal communities across the Atlantic basin—from the Caribbean to West Africa—have long documented shifts in ocean currents through oral traditions and ecological practices, framing these changes as part of a broader imbalance in marine ecosystems. Their knowledge systems emphasize the interconnectedness of currents, tides, and marine life, offering a holistic alternative to reductionist scientific models. However, these perspectives are systematically excluded from mainstream climate discourse, despite their predictive accuracy in tracking ecological shifts.

The AMOC has undergone significant slowdowns in Earth's history, most notably during the Younger Dryas (~12,000 years ago) when a massive influx of freshwater from melting glaciers disrupted global heat distribution. Proxy records from sediment cores and ice sheets reveal that such slowdowns correlate with abrupt climate shifts, including extreme weather events and ecosystem collapses. The current slowdown mirrors these patterns but occurs under anthropogenic pressure, compounding natural variability with human-induced stressors.

Comparative studies of oceanic knowledge systems reveal that Indigenous and non-Western frameworks consistently link current slowdowns to broader ecological imbalances, such as overfishing and coastal degradation. In the Pacific, traditional navigators use star paths and wave patterns to predict current shifts, a practice that aligns with modern oceanographic data but is dismissed as anecdotal. Similarly, West African fishermen's observations of 'dead zones' in upwelling currents parallel scientific findings on oxygen depletion, yet their insights are rarely integrated into policy.

Satellite data, buoy measurements, and paleoclimate records confirm a measurable slowdown in the AMOC, with a 15% decline in overturning circulation since the mid-20th century. This slowdown is driven by freshwater inputs from melting Greenland ice sheets, increased ocean stratification, and thermal expansion of seawater, all linked to anthropogenic warming. However, most models underestimate the role of localized disruptions (e.g., deep-sea trawling, offshore drilling) in accelerating these changes, highlighting gaps in interdisciplinary research.

Artistic and spiritual traditions often personify ocean currents as living entities, framing their disruption as a violation of natural law. In Haitian Vodou, the loa (spirit) Agwe is invoked to restore balance to the seas, reflecting a belief in the ocean's agency and interdependence with human actions. Similarly, Nordic sagas depict the sea as a sentient force whose currents reflect the moral health of society, a metaphor that resonates with modern ecological crises.

Future scenarios project that a 30-50% slowdown in the AMOC by 2100 could lead to regional cooling in the North Atlantic, intensified hurricanes in the Caribbean, and prolonged droughts in the Sahel. These shifts would disproportionately affect marginalized communities, exacerbating food insecurity and displacement. However, most models fail to account for non-linear tipping points, such as the collapse of Greenland's ice sheet, which could accelerate the slowdown beyond current projections.

Coastal communities in the Global South—particularly in Haiti, Senegal, and the Philippines—are already experiencing the impacts of AMOC slowdowns, including declining fish stocks and saltwater intrusion into farmlands. Their exclusion from climate negotiations reflects a broader pattern of epistemic injustice, where local knowledge is devalued in favor of Western scientific authority. Grassroots organizations, such as the Caribbean Network of Fisherfolk Organizations, are documenting these shifts but lack the resources to influence policy.