Canal Crisis: How Panama’s Drought Unraveled the Efficiency of Asia–U.S. Trade

The Panama Canal drought of 2022–2023 severely slowed Asia–U.S. container trade, adding days of delay, reducing speeds, and temporarily erasing the canal’s long-standing efficiency advantages. Heavy, draft-sensitive cargoes suffered the worst impacts, revealing how vulnerable global supply chains are to climate-driven chokepoint disruptions.

The study by the Asian Development Bank, the Hong Kong Polytechnic University, the Korea Maritime Institute, and the Technical University of Denmark investigates how the 2022–2023 Panama Canal drought disrupted one of the world’s busiest trade corridors. Using an exceptional dataset that merges 29.6 million U.S. Customs Bills of Lading with 48 million hourly AIS vessel signals, the researchers trace nearly every Asia–U.S. container shipment to reveal how a climate-linked hydrological shock brought a critical global chokepoint close to operational failure. As shown in lake-level charts on pages 5–6 of the document, Gatún Lake plunged to its lowest wet-season levels in three decades, triggering draft cuts and severe caps on daily vessel transits. These restrictions whittled the canal’s throughput down sharply, exposing the vulnerability of supply chains that rely on its normally reliable shortcut.

When Efficiency Vanishes Overnight

The study’s results show that the drought effectively wiped out the Panama Canal’s longstanding performance advantages. Under normal conditions, canal transits reduce voyage duration by 150 hours, shorten distance by 1,450 kilometers, and increase average speeds by over 7%. But as restrictions intensified from early 2023, these savings evaporated. The difference-in-differences analysis found that voyages using the canal took 133.8 extra hours, about 5.5 days, and ships spent 33 more hours stopped in queues or anchorages. Average speeds declined by 2.3 km/h, even though voyage distances remained unchanged. The event-study plots show delays escalating sharply through early 2023 and peaking in May, with voyage times growing by nearly 27% and speeds dropping 17%. Despite growing congestion, carriers rarely rerouted through Suez or the North Pacific, limited by rigid supply-chain contracts and port rotations that make sudden changes difficult.

A Climate Shock That Exposed Systemic Rigidity

One of the report’s critical insights is how little flexibility the global maritime system had when faced with the drought. Even as queues grew and cruising speeds fell, most ships stayed committed to the canal rather than shift to alternative routes. The paper argues that modern supply chains, deeply dependent on long-term contracts, fixed schedules, and equipment cycles, offer far less agility than commonly assumed. The drought thus served as a stress test for climate-related chokepoint disruption, demonstrating that a sudden environmental shock at a single waterway can destabilize vast trade flows almost instantly. The canal’s transformation from a time-saving artery to a constricted bottleneck underscores the vulnerability of Asia–U.S. trade to climate variability.

Winners, Losers, and Sector-Specific Exposure

The disruptions did not fall evenly across sectors. Heavy, draft-sensitive cargoes, especially metallic raw materials, machinery and mechanical products, and light-manufactured goods, experienced the largest delays, with penalties between 1.8 and 2.8 percentage points above the average. These products, shown clearly in the commodity breakdown charts on pages 14–15, increase vessel draft and leave carriers little room to adapt when permissible depths shrink. In contrast, perishables such as fresh fruit and vegetables, as well as petroleum and mineral products, faced no significant delay. Priority slot access for energy carriers and proactive rerouting by cold-chain shippers helped shield these categories from the worst effects. This uneven pattern reveals how chokepoint disruptions redistribute logistical burdens in ways that depend on cargo characteristics, draft requirements, and routing options.

A Warning for the Future of Global Supply Chains

The study concludes that the drought offers a glimpse of future climate-related risks. If severe weather patterns continue to intensify, global chokepoints, from Panama to Suez to key straits, will face mounting operational pressure. For Asia’s export-dependent economies, the authors recommend building resilience through dual-coast U.S. access, investments in flexible transshipment hubs, and customs fast-track lanes for highly exposed commodity groups. By linking AIS-based delay signals to trade documentation, customs authorities could strategically prioritize vulnerable sectors during disruptions. Ultimately, the drought not only delayed ships it also erased one of global trade’s most critical shortcuts and laid bare how deeply the world economy depends on infrastructure whose stability is no longer guaranteed.