Latest Data : El Niño is here and it has SMASHED all records!

Six weeks prior to this video, headlines predicting record-breaking El Niño were getting ahead of the science because forecasters were still wrestling with the spring predictability barrier, which meant there wasn't enough evidence to definitively say a super El Niño was coming.

“About six weeks ago I made a video suggesting that some of the headlines predicting a record-breaking El Niño were getting a little ahead of the science. And at that point, they probably were. The Pacific was certainly changing, but because forecasters were still wrestling with what's known as the spring predictability barrier, there simply wasn't enough evidence to justify saying we were definitely heading towards a so-called super El Niño.”

Researchers have proposed multiple contributing factors to recent spikes in sea-surface and atmospheric temperatures, including reductions in shipping sulphur emissions, unusually warm oceans across multiple basins, changes in cloud cover, and other feedbacks that scientists are still actively investigating, with no single explanation yet emerged as definitive.

“Researchers have proposed a number of contributing factors, including reductions in shipping sulphur emissions, unusually warm oceans across multiple basins, changes in cloud cover, and other feedbacks that scientists are still actively investigating. No single explanation has yet emerged as the definitive answer, and the subject remains an active area of research.”

Some models suggest that global temperatures could briefly exceed two degrees Celsius above pre-industrial times at some point next year, though this would not constitute a breach of the Paris Agreement's long-term two-degree threshold but would just be a temporary monthly spike.

“According to this recent Guardian article, some models suggest we could briefly go beyond TWO degrees Celsius above pre-industrial times at some point next year. That wouldn't mean the Paris Agreement's LONG-TERM two-degree threshold had been breached. It would just be a temporary monthly spike.”

Over the past month, forecasters obtained another month's worth of ocean temperature measurements, atmospheric observations, and satellite data, which instead of causing the various models to diverge further, has caused them to converge towards the same conclusion that El Niño could be stronger than record El Niño events of 1982-83, 1997-98, and 2015-16.

“Now forecasters have another month's worth of ocean temperature measurements. Another month's worth of atmospheric observations and another month's worth of satellite data. And instead of causing the various models to diverge even further, it's actually making them start to CONVERGE towards the same conclusion. El Niño isn't just developing. It looks like it could be stronger than the record El Niño events of nineteen eighty-two to eighty-three, nineteen-ninety-seven to ninety-eight and even twenty-fifteen to sixteen, all of which we'll come back to a bit later in the video.”

Once the Bjerknes Feedback reaches a certain level of intensity, the entire Pacific climate system can reorganize itself surprisingly quickly, which appears to be what has happened over the past few weeks.

“Once that feedback really gets going, the entire Pacific climate system can reorganise itself surprisingly quickly, which appears to be what's happened over the past few weeks.”

Previous El Niños developed in a climate that was substantially cooler than today, but in the last decade or so, the Earth's average temperature has increased by several tenths of a degree, the oceans have continued absorbing enormous amounts of excess heat, marine heatwaves have become more widespread, and global sea surface temperatures have repeatedly broken records.

“But according to the latest ensemble forecasts, this one could potentially exceed them all. Those previous El Niños all developed in a climate that was substantially cooler than todays, but in the last decade or so, the Earth's average temperature has increased by several tenths of a degree. The oceans have continued absorbing enormous amounts of excess heat. Marine heatwaves have become more widespread and global sea surface temperatures have repeatedly broken records.”

The Atlantic hurricane season is frequently suppressed during El Niño because El Niño increases vertical wind shear over the tropical Atlantic, making it more difficult for hurricanes to develop.

“And the Atlantic hurricane season is frequently suppressed because El Niño increases vertical wind shear over the tropical Atlantic, making it more difficult for hurricanes to develop.”

In parts of eastern Africa, seasonal rainfall patterns often become more intense during El Niño events.

“In parts of eastern Africa, seasonal rainfall patterns often become more intense.”

During normal years, persistent trade winds blow from east to west across the tropical Pacific, piling warm surface water around Indonesia and northern Australia, which allows colder, nutrient-rich water to rise from the deep ocean along the coast of South America through upwelling, resulting in a Pacific Ocean tilted with warm water in the west and cool water in the east.

“During a normal year, persistent trade winds blow from east to west across the tropical Pacific, piling warm surface water up around Indonesia and northern Australia. That allows colder, nutrient-rich water to rise from the deep ocean along the coast of South America in a process known as upwelling. The result is a Pacific Ocean that's effectively tilted. Warm in the west. Cool in the east.”

Every few years the balance between trade winds and ocean temperature breaks down as trade winds weaken and sometimes reverse, allowing the enormous reservoir of heat built beneath the western Pacific to move back towards South America via equatorial Kelvin waves.

“But every few years that balance begins to break down. The trade winds weaken and sometimes even reverse for short periods of time. Without those winds continually pushing warm water westwards, the enormous reservoir of heat that's been building beneath the western Pacific begins to move back towards South America via enormous underwater pulses known as equatorial Kelvin waves.”

As equatorial Kelvin waves move across the Pacific, they deepen the thermocline, which is the boundary separating warm surface water from the colder ocean beneath, suppressing normal upwelling of cool water along the equator and allowing sea surface temperatures to rise.

“As they move across the Pacific they deepen the thermocline, which is the boundary separating warm surface water from the colder ocean beneath. That suppresses the normal upwelling of cool water along the equator and allows sea surface temperatures to rise.”

During strong El Niño events, Indonesia and parts of northern Australia typically see increased risk of drought and wildfire.

“Across Indonesia and parts of northern Australia, the risk of drought and wildfire typically increases during strong El Niño events.”

Along the west coast of South America, warmer ocean waters during El Niño can bring exceptionally heavy rainfall and flooding.

“Along the west coast of South America, warmer ocean waters can bring exceptionally heavy rainfall and flooding.”

Once surface waters begin warming during El Niño, they heat the atmosphere above them, which weakens the trade winds even further, allowing more warm water to move east and weaken the winds more, creating a classic positive feedback loop known as the Bjerknes Feedback, named after Norwegian meteorologist Jacob Bjerknes.

“Once the SURFACE waters begin warming, they heat up the atmosphere above them. That weakens the trade winds even further. Which allows still more warm water to move east, which weakens the winds even more. It's a classic positive feedback loop, isn't it? In fact, this one even has a name. It's called the Bjerknes Feedback, named after the Norwegian meteorologist Jacob Bjerknes, who first explained how the ocean and atmosphere reinforce one another during El Niño events.”

According to recent modeling, 2027 could become the warmest year on record by some margin due to the delayed warming response from the current strong El Niño event.

“That could make twenty-twenty-seven the warmest year on record by some margin.”

Trade winds across parts of the equatorial Pacific have weakened substantially, several powerful downwelling Kelvin waves have propagated eastwards beneath the surface, subsurface heat content across the central and eastern Pacific has increased dramatically, and the multi-model median for peak sea surface temperature anomaly in the Niño 3.4 region currently stands at 3.6 degrees Celsius.

“Trade winds across parts of the equatorial Pacific have weakened substantially. Several powerful downwelling Kelvin waves have propagated eastwards beneath the surface. Subsurface heat content across the central and eastern Pacific has increased dramatically. And the so-called multi-model median for the event's peak sea surface temperature anomaly in the Niño 3.4 region, which is the standard index used to monitor El Niño, currently stands at three-point-six degrees Celsius.”

When the previous video was made, ensemble forecasts showed a wide spread of possible outcomes ranging from moderate to strong El Niño with some outliers hinting at something exceptional, and this range was largely due to the spring predictability barrier.

“When I made my previous video, those ensembles still showed quite a wide spread of possible outcomes, ranging from a moderate El Niño to a strong one, with some outliers hinting at something exceptional. And that range was pretty much all to do with that Spring Predictability Barrier that I mentioned earlier.”

Climate scientist Zeke Hausfather has earned a reputation as one of the more cautious interpreters of climate data who frequently urges journalists and sometimes fellow scientists not to jump to conclusions before evidence is sufficiently robust.

“If you've followed Zeke's work over the years, you'll know that he's earned a reputation as one of the more cautious interpreters of climate data. He's frequently the person urging journalists—and sometimes even fellow scientists—not to jump to conclusions before the evidence is sufficiently robust.”

The temporary possibility of reaching 2 degrees Celsius above pre-industrial times makes the Paris Agreement's lower 1.5 degree Celsius target look even more obsolete than it already was.

“it does kind of make the lower one-point-FIVE-degree target look even more obsolete than it already was, don't you think?”

Fourteen of the world's leading seasonal prediction systems have collectively generated six hundred and sixty-seven individual ensemble simulations of how tropical Pacific conditions are likely to evolve over the coming months.

“Hausfather has gone to the trouble of collating the latest forecasts from fourteen of the world's leading seasonal prediction systems into what the science types call an ensemble. Collectively, those fourteen forecasting systems generated six hundred and sixty-seven individual ensemble simulations of how conditions in the tropical Pacific are likely to evolve over the coming months.”