On Wednesday, the UN will hold a rare donor meeting in the hope of raising the $80 million needed to avoid an old oil tanker off Yemen's west coast from exploding and triggering an environmental calamity four times greater than the Exxon Valdez spill in 1989.

The funds are needed to dump more than 1.14 million barrels of oil that have been lying in the dilapidated cargo ship Safer for more than six years due to a dispute over ownership and accountability between the Yemeni Armed Forces and the Saudi-backed coalition.

The ship, according to experts and activists, is an unexploded timebomb that might cause an ecological disaster. According to UN estimates, if the ship's cargo is released into the Red Sea, more than 200,000 fishermen will lose their employment, and a clean-up effort will cost $20 billion.

An international donor conference will seek to gather the requisite $80 million to unload the light crude oil under a new arrangement negotiated over six months by UN and Dutch diplomats. The idea was conceived by David Gressly, the UN resident coordinator and humanitarian coordinator for Yemen.

The Yemeni Armed Forces signed a memorandum of understanding on March 5 that authorizes the UN to transfer around 1.1 million barrels of oil from the ship.

The oil would be moved to a safe vessel that would stay put. Within 18 months, a new ship would be bought for the Yemeni Armed Forces to replace Safer, ensuring that they would be able to operate a thriving oil export enterprise once the civil war is over. The Safer vessel would be towed and sold for scrap. 

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Gressly said the crisis was a high-priority one since “in March, a UN-led mission to the Ras Isa peninsula confirmed that the 45-year-old supertanker is rapidly decaying. It is at imminent risk of spilling a massive amount of oil due to leakages or an explosion”. The ship's inert air, which ordinarily prevents an explosion, has disappeared, according to the UN.

“While some may question the $80m price tag of the UN-mediated plan to address the threat posed by the FSO Safer, the costs of inaction – which start at $20bn for managing the consequences of a catastrophic spill – are far, far greater. The world has watched this situation grow more dangerous with every passing month, and it’s vital that donors provide the money that is needed to allow this urgent plan to proceed this summer,” the Conflict and Environment Observatory's Doug Weir said.

The UN plan, according to Greenpeace, must be carried out before October, "when the wind and the currents will be too dangerous and hinder any rescue operation. Lack of funding cannot be an excuse to fail."

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Since Yemen's war began in 2015, no structural repairs have been made to the 376-meter-long vessel, which was built in 1976 as an oil tanker and modified a decade later to be a floating storage facility for oil. It has 36 distinct oil storage tanks with a combined capacity of almost three million barrels.

Since diesel fuel has been scarce for some years, Safer's engines have not been started, and the building has been exposed to humidity and rust with little or no maintenance.

A major spill would compel the closure of the ports of Al-Hudaydah and Salif, which are critical for commercial imports and humanitarian aid. The environmental impact might harm Saudi Arabia, Somalia, Djibouti, and Eritrea as well as impede shipping in the Bab al-Mandab Strait and the Red Sea, depending on the season and prevailing wind and currents. Coral reefs, coastal mangroves, and numerous endemic species remain abundant in the Red Sea.

The donor meeting comes after the first nationwide ceasefire since the war began in Yemen.