Cách một hiện tượng El Niño trở thành siêu El Niño

El Niño has begun and forecasters predict a more than 60% chance that the naturally occurring phenomenon could become a very strong, or super El Niño later in 2026.

El Niño begins with warmer water in the Pacific Ocean near the equator and can have a cascade of dramatic effects on the world’s weather.

But what chain of events has to happen for high temperatures in the Pacific to translate into severe floods, droughts and storms around the world? And what role does climate change play in El Niño?

In this episode of The Conversation Weekly podcast, Ioana Colfescu, an expert in climate and machine learning at the University of St Andrews and the University of Edinburgh, explains how El Niño works and what it could mean for the world.

In the early 1600s, fishermen in Peru and Ecuador noticed something unusual. Their nets were usually flush with anchovies which thrive in the cold waters of the Pacific Ocean. But every few years, the waters began to turn warmer, driving the anchovies away. They called this phenomenon El Niño, meaning little boy, or Christ child, because it tends to peak around Christmas time.

Centuries later, scientists would understand that this warmer water in the equatorial Pacific is part of a naturally occurring cycle and they would start trying to predict when the next one was coming and how bad it would be.

“We have indicators that place this El Niño in a similar pattern or signs that other very large El Niños had,” says Colfescu. “But while we know it’s gonna be a big event in terms of temperature, this temperature index is not yet defined as a big event in terms of impact.”

The 2023-24 El Niño was one of the top five strongest ever recorded. While it dramatically affected some parts of the world, including severe flooding in Brazil, and also contributed to 2024 being the hottest year ever recorded, some of the expected effects did not materialise. Colfescu says that’s because El Niño’s “impacts are nuanced … and the response across the tropics, can be different to the one [outside the] tropics”.

Whatever severe weather conditions do happen, Colfescu says they’re likely to be “made much worse because the El Niño right now is overlapped on an already warm ocean because of climate change.”

Listen to Colfescu explain the mechanisms behind El Niño on The Conversation Weekly podcast.

This episode of The Conversation Weekly was written and produced by Gemma Ware and Mend Mariwany. Mixing by Eleanor Brezzi and theme music by Neeta Sarl.

Newsclips in this episode from Al Jazeera English, KCRA 3, Bloomberg-News, CBC News and DW News.

Listen to The Conversation Weekly via any of the apps listed above, download it directly via our RSS feed or find out how else to listen here. A transcript of this episode is available via the Apple Podcasts or Spotify apps.

Ioana Colfescu is the Digital Atmosphere Programme Leader at the National Centre for Atmospheric Science, which has also provided her with research funding.