Forces of Change
Periodically, the western Pacific Ocean warms. Weather changes around the world. It's an El Niño. Discover its early warning signs, its ancient past, its global connections, and its good — as well as its bad — consequences.
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What is El Niño?

El Niño events occur in the Pacific Ocean but can disrupt weather patterns worldwide. Discover the causes and characteristics of El Niño events.


Clues From the Past

El Niño may seem new to many of us. But scientists have evidence that suggests El Niño events have happened for at least 40,000 years. Discover the clues that can reveal El Niños of the past.


Long Distance Connections

El Niño and La Niña impact weather in different parts of the world and at different times. Discover these global impacts.


Winners & Losers

During an El Niño, sea temperatures climb, triggering torrential rains in typically dry climates. What becomes a disaster for some animals proves a bonanza for others.


The Lowdown on El Niño

How well do you know El Niño? Study a recent satellite image to see if an El Niño is coming. Learn little-known facts about El Niño's world-wide impacts.