Union of Comoros Maritime Corridor Development & Regional Trade Facilitation

Adaptation Need

GCA’s analysis revealed that the ports of Moroni, Boingoma, and Mutsamudu are highly vulnerable to climate hazards such as sea level rise, storm surges, cyclonic winds, and intense rainfall, which threaten operations and increase maintenance costs. Rising temperatures and ocean acidification further accelerate infrastructure degradation. For example, under the more extreme SSP5-8.5 scenario, projected increases are 0.8°C, 2.2°C, and 3.3°C, respectively. Given Comoros’ reliance on imports and fishing, port disruptions pose serious risks to economic stability and trade efficiency. Without urgent adaptation measures, climate-induced damages could escalate dramatically by 2080, with estimated delayed cargo of approximately $867,000 per extreme weather event per port at major ports.

GCA’s Added Value

To address these challenges, GCA’s cost-benefit analysis prioritized economically viable adaptation measures. Grey infrastructure solutions, such as raising breakwaters, proved most effective for Moroni and Boingoma, with a high Benefit-Cost Ratio (BCR) of 6.59. For Moroni, a green solution—an artificial reef—was also proposed, showing a positive BCR of 2.45. In Mutsamudu, an ecological wastewater treatment system was recommended as a nature-based approach. GCA also identified options for improved climate monitoring, governance, port planning, and community engagement to ensure long-term maritime resilience. GCA is supporting the integration of the most cost-effective adaptation options within the AfDB Investment project by providing a financial rationale for the proposed adaptation options.