Drought saps the Panama Canal, disrupting global trade – can El Niño already be a factor?

Ship passing through the new Agua Clara Locks, Panama Canal [image credit: Mariordo @ Wikipedia]

Having stated water levels in the canal have been a problem for a number of years, blaming the recently arrived El Niño seems a bit strange, and the last significant one ended in 2016. One expert is quoted saying it could be a source of drought, which implies some uncertainty. Using seawater to top up the canal isn’t an option for ecological reasons. Every vessel passage uses a lot of water (200 million litres per ship as an average), and capacity was doubled in 2016.
– – –
For over a century, the Panama Canal has provided a convenient way for ships to move between the Pacific and Atlantic Oceans, helping to speed up international trade, says the Houston Herald.

But a drought has left the canal without enough water, which is used to raise and lower ships, forcing officials to slash the number of vessels they allow through.

That has created expensive headaches for shipping companies and raised difficult questions about water use in Panama. The passage of one ship is estimated to consume as much water as half a million Panamanians use in one day.

“This is the worst we have seen in terms of disruption,” said Oystein Kalleklev, the chief executive of Avance Gas, which transports propane from the United States to Asia.

The problems at the Panama Canal, an engineering marvel that opened in 1914 and handles an estimated 5 percent of seaborne trade, is the latest example of how crucial parts of global supply chains can suddenly seize up.

In 2021, one of the largest container ships ever built got stuck for days in the Suez Canal, choking off trade. And the huge demand for goods like surgical masks, home appliances and garden equipment during the pandemic strained supply chains to their breaking point.

In Panama, a lack of water has hampered canal operations in recent years, and some shipping experts say vessels may soon have to avoid the canal altogether if the problem gets worse. Fewer passages could deprive Panama’s government of tens of millions of dollars in annual revenue, push up the cost of shipping and increase greenhouse gas emissions when ships travel longer routes.

Though Panama has an equatorial climate that makes it one of the wettest countries, rainfall there has been 30 percent below average this year, causing water levels to plunge in the lakes that feed the canal and its mighty locks.

The immediate cause is the El Niño climate phenomenon, which initially causes hotter and drier weather in Panama, but scientists believe that climate change may be prolonging dry spells and raising temperatures in the region.

Before the water problems, as many as 38 ships a day moved through the canal, which was built by the United States and remained under its control until 2000. The canal authority in July cut the average to 32 vessels, and later announced that the number would drop to 31 on Nov. 1.

Further reductions could come if water levels remain low. The canal authority is also limiting how far a ship’s hull can go below the water, known as its draft, which significantly reduces the weight it can carry.
. . .
But traffic through the canal is likely to remain at lower levels in the coming months. Reducing passages helps conserve water, because huge amounts are used up every time a ship goes through the locks as it travels the 40 miles across Panama.

The drought also presents tough choices for Panama’s leaders, who must balance the water needs of the canal with those of residents, over half of whom rely on the same sources of water that feed the canal.
. . .
Because interest in building a canal dates to the 19th century, Panama has rainfall records going back some 140 years. That gives scientists more confidence when concluding that a weather change is a permanent shift and not merely random, said Steven Paton, a director of the Smithsonian Tropical Research Institute’s Physical Monitoring Program on an island in Lake Gatun, which makes up a large part of the canal and supplies most of its water.

He said that while scientists were unsure about climate change’s impact on El Niño, two of the driest El Niño periods of the last 140 years had occurred in the last quarter-century, and that the current one could be the third.

“It doesn’t say that this is climate change,” Mr. Paton said, “but it does say that this is wholly consistent with almost all of the climate change models.”

Full article here.