CARIBBEAN-Caribbean countries urged to adopt policies to deal with a weakening AMOC.

BELMOPAN, Belize, CMC – A former executive director of the Belize-based Caribbean Regional Fisheries Mechanism (CRFM), says Caribbean Community (CARICOM) countries must keep pressing the international community to more aggressively address global warming by implementing deep cuts to fossil fuel emissions and transitioning to a low carbon global economy to avoid the catastrophic impact of a weakening Atlantic Meridional Overturning Circulation (AMOC).

The AMOC is a powerful system of ocean currents in the Atlantic Ocean, often described as a massive ocean conveyor belt. It transports a vast amount of warm, salty surface water from the tropics and southern Atlantic northward to the Arctic.

As this water reaches higher latitudes, it cools, becomes denser, and sinks into the deep ocean, beginning a southward return journey to the tropics and southern hemisphere.

Milton Haughton, who now serves as a consultant to the CRFM, said that as the 30th United Nations climate conference (COP 30) gets underway in Belém, Brazil, on Thursday, it is essential for the region to adopt a position on the issue.

“For CARICOM states, which already face existential threats from increasingly powerful hurricanes, sea-level rise, altered rainfall patterns, and destabilization of coastal ecosystems and marine living resources, the demise of the AMOC could have dire and immediate consequences, demanding urgent attention from the international community and national and regional policy-makers.”

He warned that a weakening AMOC would raise sea level in the Caribbean region via changes in ocean dynamic height and current redistribution, increasing erosion, saltwater intrusion, and flood risk in coastal communities.

“A weakening AMOC is likely to result in a shift in the tropical rain belt -the Intertropical Convergence Zone (ITCZ)-potentially altering the timing, amplitude, or spatial pattern of rainfall in the region, impacting freshwater resources, agriculture, tourism, and terrestrial and marine ecosystems’ health.”

Haughton said that based on observational studies, the weakening AMOC is already causing significant changes to ocean conditions and the health of marine ecosystems. He said that warming water, changes in salinity, acidity, oxygen, water-column stratification, and ocean current movement are already underway.

“Marine species are already suffering from increased heat stress and altered nutrient flows associated with these oceanographic changes. These factors together with marine pollution are likely contributing to observed coral bleaching, queen conch reproduction failure in coastal waters, sargassum and other harmful algal blooms (e.g. red tide), as well as changes in commercial fish and shellfish reproduction, larval transport and settlement, population connectivity, distribution and abundance across the region.”

He said scientists have acknowledged the high levels of uncertainty and risk associated with many models used to predict changes in the AMOC and its impacts, due to biases and limited data.

“However, they have also noted that the “worst case” of AMOC weakening for the Caribbean may be worse than many published projections. For adaptation, the Caribbean should therefore consider both moderate and high‐impact scenarios, and embark on a more aggressive program to implement the reforms needed to secure a resilient and prosperous future,” Haughton said.

The UN Intergovernmental Panel on Climate Change (IPCC) in its 2019 Special Report on the Ocean and Cryosphere in a Changing Climate, reported that the AMOC would weaken during this century. Still, total collapse was unlikely under even the worst-case warming scenarios. However, more recent scientific evidence has been raising an alarm that the weakening of the

The critical Atlantic meridional overturning circulation system is occurring much faster than initially projected due to climate change and can no longer be considered a low-likelihood event this century.

“The demise of this vital ocean circulation system poses a severe, systemic risk to the small, vulnerable CARICOM States and territories,” Haughton said, adding that comprehensive, holistic, integrated, multi-sectoral policies and actions are required.

“It is not too late,” he said.