Picture 200 million litres of freshwater — gone. That is what it costs every time a single ship squeezes through the Panama Canal's locks, and right now there is barely enough water to keep that system running. El Niño, the climate phenomenon that warms the central and eastern equatorial Pacific and scrambles weather patterns across the planet, has pushed rainfall at the canal to 35.8% below its historical average between April and August.

Panama has declared a national emergency, and on Friday the canal cut daily ship transits from 36 to 32 — only the second time in its history that such a restriction has been imposed. Why does a ship need freshwater to cross an ocean? Because the Panama Canal's ingenious lock system — which physically lifts and lowers vessels over the continental divide — is powered entirely by gravity-fed lakes that depend on rain. The canal's water manager, Erick Cordoba, put it bluntly: there are no signs of recovery in the short term.

Authorities have also reduced the permitted depth at which ships may sit in the water, from 15.24 to 14.63 metres, meaning heavier, more loaded vessels simply cannot enter. Forecasts suggest the next dry season, normally January to April, will arrive early and stretch into May 2027.

The ripple effects reach far beyond Central America. Roughly 5% of all global trade moves through this 80-kilometre waterway connecting the Pacific and the Atlantic. When El Niño last tightened its grip in 2023 and 2024, daily transits fell to just 22 ships, tonnage dropped 17%, and long queues of waiting vessels became a common sight off both coasts.