A 47-year-old ship could cause "one of the worst oil spills in human history." Here's the plan to stop it.

The United Nations officially launched its mission this week to prevent what it says could be an "environmental catastrophe" on the Red Sea. Sitting off the coast of Yemen lies a nearly half-century-old ship with roughly 1.14 million barrels of crude oil on board, the global agency said – and it's "deteriorating rapidly." 

The massive 47-year-old supertanker, FSO Safer, rests just about 5 1/2 miles off of Yemen's coast, where it has gone without maintenance for seven years. 

"Its structural integrity is compromised, and it is deteriorating rapidly," the U.N. says. "There is a serious risk the vessel could be struck by a floating mine, spontaneously explode or break apart at any moment." 

Officials have been pushing for the situation to be addressed for years. In 2020, the U.N.'s Environment executive director Inger Andersen warned that if the oil on that ship was to leak into the water, it could unleash four times more oil than what was released in Alaska's Exxon Valdez oil spill of 1989, which affected more than 1,300 miles of shoreline and killed thousands of birds and sea otters, hundreds of seals and nearly two dozen killer whales. 

To this day, several species are still considered not to have recovered from the incident, according to NOAA, and the spill was one of the nation's biggest environmental disasters in recent history.

And it would only be an added strain on the region's environment. On Africa's West Coast, millions of barrels of oil have been spilled in the Niger Delta for decades, leading to environmental damage, lawsuits and protests.

If this tanker were to burst open, the U.N. estimates it would cost $20 billion to clean up and could affect 17 million people while destroying coral reefs, mangroves and other forms of sea life, making it "one of the worst oil spills in human history."

"Coastal communities would be hit hardest. Hundreds of thousands of jobs in the fishing industry would be lost almost overnight," the U.N. says. "It would take 25 years for fish stocks to recover."

How did FSO Safer get stuck in the Red Sea? 

The current situation is rooted in the Yemen civil war, which has been ongoing since 2014. When that war began between the country's government and Houthi rebels, the ship became a bargaining trip for the two sides. The back-and-forth ended up putting a halt to all operations on the ship in 2015. 

What is the U.N.'s plan to address the problem? 

The official launch of the mission to prevent such a disaster comes a year after the U.N. started an online crowdfunding campaign to raise the money to do so. They have estimated it will cost about $144 million to complete the mission, and while the U.N. has much of that on hand, they say they still need $24 million to fully fund the effort.

But even with that gap, this week they commenced the "high-risk," two-part operation. 

The initial step, dubbed the "emergency phase," entails transferring the oil from the tanker to a new vessel, named Nautica. The crew that will be inspecting the aging vessel arrived on-site on May 30. As of Friday morning Eastern Time, Nautica was situated off the coast of Djibouti, East Africa, where officials say it will remain until Safer is deemed ready to transfer its oil. 

In the second phase, Nautica – with the oil onboard – will be connected to a catenary anchor leg mooring buoy, which is designed to handle large vessels such as this, to take the ship's place in its spot in the Red Sea. FSO Safer, which even though emptied will still have "a considerable amount of residual oil and pose a significant environmental threat," will then be towed to a scrap yard. 

While the U.N. has been raising money for this mission, officials say $29 million is still needed. 

"This is a great milestone," U.N. humanitarian coordinator David Gressly said, "but we will not rest easy until the operation is completed."

Amjad Tadros contributed to this report.

In:
• Oil Spill
• Yemen
• Middle East
• Oil and Gas
• Exxon Mobil

Li Cohen

Li Cohen is a social media producer and trending content writer for CBS News.