The Christ Child's Current: How Peruvian Fishermen Named El Niño

Every summer along the arid coast of northern Peru, the fishermen of Paita watched the sea change. The cold, fish-rich waters that sustained their livelihoods would give way, for a few weeks, to a warm current flowing south along the shore. It tended to arrive around Christmas. So the fishermen — who had been observing it since at least the 1600s — gave it a name suited to the season: El Niño de Navidad, the Christ Child.

They could not have known that their local nickname for a seasonal current would one day label a planet-spanning climate phenomenon, invoked in headlines from Jakarta to Nairobi to Sacramento. The story of how that happened begins with a catastrophe.

The flood year of 1891

In 1891, the Peruvian coast was hit by an El Niño event of catastrophic proportions. Torrential rains fell on a coastline that is normally among the driest places on Earth. The deserts bloomed. Fish species no one on the coast recognized appeared in the warm waters offshore. For the fishing communities of the north, it was a world turned upside down.

The disaster caught the attention of Lima's scientific establishment. Dr. Luis Carranza, President of the Sociedad Geográfica de Lima — the geographical society founded just three years earlier, in 1888 — published a note in the Society's Bulletin describing a north-to-south countercurrent observed between the ports of Paita and Pacasmayo. Crucially, Carranza connected the current to the torrential rains of that catastrophic year. It was the first time the phenomenon had been formally described in a scientific publication, though Carranza did not yet use the fishermen's name for it.

Captain Carrillo names the current

The name arrived the following year. In 1892, Captain Camilo N. Carrillo — a Peruvian naval hydrographer who lived from 1830 to 1900 — addressed the geographical society congress. He explained that the sailors of the northern coast called the warm seasonal current "El Niño," because it was most visible around Christmas.

With that address, a folk name spoken in the fishing ports of Peru for centuries entered the scientific literature. It has never left.

It is worth pausing on what Carrillo and Carranza actually meant by "El Niño." To them, and to the fishermen, it was a purely local affair: a modest, warm, south-flowing countercurrent that appeared off northern Peru each year around the holidays. In most years it was mild and unremarkable. Only occasionally — as in 1891 — did the warming become extreme, the rains torrential, and the consequences catastrophic.

From local current to global phenomenon

Over the course of the 20th century, the meaning of the term shifted. Scientists gradually realized that the exceptional warm years off Peru were not a local quirk but the coastal signature of something vastly larger: a periodic warming that spans the entire equatorial Pacific, coupled to a see-saw in atmospheric pressure that the British scientist Gilbert Walker would call the Southern Oscillation. The decisive intellectual connection came in 1969, when Jacob Bjerknes showed the ocean warming and the atmospheric oscillation were one coupled system — a story told in our article on Walker and Bjerknes.

As the science broadened, so did the name. "El Niño" stopped meaning the gentle Christmas current and came to mean the basin-wide warm phase of what is now called the El Niño–Southern Oscillation, or ENSO. The original usage survives mainly in histories like this one, and in the memory of Peru's coastal communities.

Why the fishermen were right all along

There is something fitting in the fact that the global term preserves the fishermen's perspective. The people of Paita were not simply naming a curiosity; they were recording, generation after generation, a genuine environmental signal with real consequences for their lives. When the warm water came in strong, the anchoveta and the cold-water fish went elsewhere, seabirds starved, and — in the great years — the rains came to the desert.

Modern science has confirmed the pattern they saw and traced its reach across the globe. Reconstructions from lake sediments, corals and tree rings show ENSO has been operating for more than 10,000 years — far longer than anyone has been naming it. And events like the one that alarmed Carranza in 1891 have recurred again and again, from the devastating famines of 1877-78 to the "super" El Niños of 1982-83, 1997-98 and 2015-16, all charted in the full event timeline.

The next time you read a forecast invoking El Niño, remember where the word comes from: not a laboratory or a satellite mission, but fishermen on a desert coast, watching the sea warm at Christmas, and naming what they saw after the season's child.