A recurring Pacific climate cycle — the warm phase of El Niño–Southern Oscillation — in which warm surface water shifts east every few years, suppressing the cold upwelling off Peru and reshaping weather worldwide: drought in Australia and South Asia, floods in South America, weakened monsoons and famine in Africa and India. Spanish sailors named it for the Christ Child. Mike Davis’s Late Victorian Holocausts argues that the great colonial-era famines came from these cycles colliding with imperial economies that left subject populations no buffer.
Every few years, the Pacific Ocean changes direction. The warm water that normally sits far to the west slides east toward South America, and the whole planet feels it. Australia goes dry. Peru floods. India's monsoon weakens. And in the worst years, tens of millions of people starve. The Spanish sailors who first noticed the warm current arriving around Christmas named it El Nino, the Christ Child. They had no idea they had put a name on one of the most powerful forces in the climate system.