EXPLAINED IN 92 SECONDS
WHAT IT IS
Can a patch of water in the Pacific really have an influence on the globe’s weather? You bet. El Niño is a stretch of unusually warm water that forms off the coast of Peru and stretches across the equatorial Pacific every 3-7 years. The opposite phase, La Niña, displays a similar pattern but with cooler-than-normal water. These oceanic shifts conspire with the atmosphere to alter global weather by increasing the odds of drought, heavy rain and cool or hot temperatures in different parts of the world.
WHY IT'S IMPORTANT
El Niño and La Niña help tip the odds for all kinds of weather shifts around the planet. Globally, El Niño tends to boost temperatures and likely contributed to 2014’s record heat. There are also regional impacts. In the southern tier of the U.S., El Niño tends to bring heavy rains while La Niña brings drought conditions. In Australia, La Niña can bring torrential downpours. During a particularly strong La Niña in 2011, it rained so much in Australia that sea level rise actually slowed. El Niño has the power to help start droughts, bust them, break temperature records and have all sorts of impacts on people living in all corners of the globe. In the future, climate change could double the likelihood of both extreme El Niño and La Niña events.