Quadra Project: The Panama Canal

The Panama Canal and the Suez Canal are both magnificent feats of engineering that allow marine shipping to move east and west across the mid-latitudes without having to make the long journey around the continents of South America and Africa, respectively. The Suez is mostly a big ditch that was dredged in the sand to connect the Mediterranean to the Red Sea. No locks are required because the two seas are at the same elevation. Building the Panama Canal, however, was a much more complicated engineering problem, solved with remarkable ingenuity.

The distance from the Atlantic to the Pacific at the isthmus of Panama is 65km. It is traversed by going up 26 metres through the three Gatun locks, crossing 33 km of Gatun Lake made by damming the Chagres River, and then descending to the Pacific by passing through Pedro Miguel and Miraflores locks.

When the Panama Canal was finished in 1914, the degree of planning and work was momentous. Passages between mountains had to be dug. And the Chagres River had to be dammed to form a lake that was deep enough to allow the transit of great ocean-going vessels. But the genius was in how it actually worked.

As one of the wettest countries in the world, Panama had a generous supply of rain that fed the Chagres River. By damming the river and the exits, the water formed a lake, and the excess that would have overflowed was now used to operate the locks. For each of the 22 vessels per day passing through the canal in 2023, the locks required about 170 million litres per transit.

The system worked flawlessly for a century. But no one imagined more than 100 years ago that rain patterns would ever be different. A few years ago, however, due to global climate change, Panama began to experience droughts. This meant that the water supply that operated the locks was insufficient to meet the traffic needs. As the necessary water was drained off to operate the locks, parts of Gatun Lake became too shallow for vessels to transit. In 2023, one of the worst for erratic rainfall, the year began with more precipitation than the canal could use, but ended with a record drought. Traffic in the canal was reduced by 30 percent. Some vessels had to offload and transport cargo by train across the isthmus so the ships would float high enough to traverse Gatun Lake. Some had to wait for weeks for transit because of the traffic slowdown.

Other larger vessels could not pass through the canal whatever they did. They either had to abandon their shipping or go around the tip of South America. For traffic between the East Coast of the United States and Japan, this added another 4,800 km to the journey. For bananas travelling from Ecuador to Europe, this meant another 8,000 km of travel.

This is a sample of the unexpected consequences of climate change. We build infrastructure based on the climate reliability that has been functioning for the last 12,000 years of the Holocene. This reliability has supported our agricultural endeavours, allowed industrialized food production, permitted us to build our settlements and cities with their burgeoning populations beside rivers and along coastal lowlands. The 8-plus billion of us that now inhabit our planet are being faced with unsettling new conditions that will invalidate our old assumptions of reliability that we knew and trusted.

Rivers that provide irrigation are more frequently either flooding or going dry. Many cities that relied on drinking water are now finding that they do not have enough supplies to be viable—as one sample of many, the 22 million people of Mexico City are suffering water shortages. As glaciers melt and snowfall diminishes, mountains will become less reliable water supplies. Some heavily populated swaths of the planet will become too hot for permanent occupation. Sea level rise, expected to be about a metre by 2100, is a situation that will either threaten or displace thousands of coastal communities. The gravitational drainage systems of New York and Miami will become inoperable. In about 130 years, London is expected to be awash in seawater. Valuable coastal farmland will be polluted with salinity.

The Panama Canal is an instructional example of what can go wrong when we alter the fundamental ecological structures that we have relied on for centuries. Indeed, the recent increase in the cost of living cannot be separated from changes in weather patterns that are inhibiting food production, of weather anomalies that are raising insurance rates, of geopolitical unrest that is being exacerbated by climate refugees.

Environmentalism has become both an ethical and a security issue. This is something we need to consider when we choose to travel unnecessarily, eat excessive amounts of meat, buy thoughtlessly, and waste heedlessly.

The Panama Canal is a surprising example of how wrong things can go in the new climate reality we have invented. But, on the positive side, as ocean levels rise, the Suez Canal will get deeper without anyone having to dig.

Ray Grigg for Sierra Quadra

Photo credit: Panama Canal – Photo by haluk ermis via Flickr (CC By 2.0)

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