As summer approaches, chances are rising for one of the strongest El Niño events in history. Forecasters are growing increasingly confident that this temporary warming of the tropical Pacific Ocean will set a new global temperature record, but what does that mean for the climate crisis?
El Niño events are now unfolding against the backdrop of human-driven climate change. The relationship between these forces is highly complex, and researchers are still working to understand exactly how they influence each other. But in recent years, it’s become evident El Niño can compound the warming effects of rising greenhouse gas concentrations, helping boost the global average temperature into uncharted territory.
As humanity continues to pump the atmosphere full of carbon, the impacts of El Niño will likely become more severe, and the climate will have a harder time recovering from these cyclical temperature surges. Let’s unpack what this all means and how a potentially extreme El Niño could impact our rapidly warming world.
Understanding El Niño
The El Niño-Southern Oscillation (ENSO) is a recurring climate pattern that cycles between periods of cool (La Niña) and warm (El Niño) sea surface temperatures in the central and eastern tropical Pacific. This cycle is irregular, with El Niño and La Niña events occurring on average every two to seven years, according to the National Oceanic and Atmospheric Administration (NOAA).
ENSO is the biggest year-to-year climatic variation on the planet. “It’s the 800-pound gorilla in the climate zoo,” Michael Mcphaden, a senior scientist at NOAA, told Gizmodo. This cycle alters atmospheric circulation, which in turn influences temperatures and precipitation across the globe.
During El Niño, sea surface temperatures in the central and eastern tropical Pacific rise above average, pumping extra heat into the atmosphere and shifting the Pacific jet stream southward. As a result, the global temperature rises and various regions of the world experience significant changes in weather patterns. In many places, El Niño exacerbates extreme weather events that are already growing more frequent and severe due to human-driven climate change.
“We have terrestrial heat waves that are very deadly, significant public health hazards, we have intensified storms, we have more extreme droughts,” Mcphaden explained. “These are due to the combination of El Niño and climate change at a particular period of time.”
Compounded warming
A strong El Niño that developed in 2023 played a key role in making 2024 the hottest year on record. When La Niña took hold in 2025, the global average temperature fell, but it did not return to 2022 levels. In fact, 2025 became the third-warmest year on record, just behind 2023 and 2024. That’s because more greenhouse gases had accumulated in the atmosphere, essentially counteracting the global cooling effect of La Niña, Mcphaden explained.
This dynamic shows up in unusual regional-scale weather patterns. “Earlier this year, when it was still a La Niña, we had a massive heat wave in Australia even though usually La Niña means Australia is cool. So the anthropogenic effect really counteracted the effects of [La Niña],” Friederike Otto, a climate science professor at Imperial College London, told Gizmodo.
This pattern also appears in historical temperature records. “La Niña years in the 21st century are warmer than El Niño years in the 20th century because of the accumulation of greenhouse gases,” Mcphaden said.
That underscores why the historical temperature record looks more like a rising staircase than a smooth incline. In a 2023 article for The Conversation, Kevin Trenberth, a Distinguished Scholar at the National Center of Atmospheric Research, explained that global warming follows a step-like progression that’s heavily influenced by ENSO variability. El Niño years cause global average temperature to spike, followed by a cooling La Niña. But due to rising concentrations of greenhouse gases in the atmosphere, the net long-term effect is still warming.
According to the most severe model projections, this year’s El Niño could be even stronger than the 2023 event. All the experts Gizmodo spoke to for this story expressed confidence that a super El Niño could cause global temperatures to rise more than 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels in 2026 and 2027. That’s the benchmark established by the Paris Climate Agreement for limiting the worst impacts of climate change.
“It is possible that a really big El Niño event right now essentially pushes us to a point where we only infrequently—if ever—get back below that 1.5-degree C [2.7-degree F] level,” Daniel Swain, a climate scientist at the University of California Agriculture and Natural Resources, told Gizmodo.
But perhaps more importantly, the extreme weather we experience during a super El Niño would be a preview of the world we will be living in permanently in just five or 10 years, according to Swain. “As a climate scientist, that’s a profoundly alarming realization,” he said.
More frequent super El Niños?
It’s clear that El Niño plays an influential role in global temperature rise, but whether the reverse is true remains an open question. With that said, there is some evidence to suggest that human-driven climate change may be leading to a higher frequency of strong El Niño events.
“They occur infrequently enough that it’s impossible to get a statistically significant sample size from observations at this point, but the numbers do show that we may be seeing more extreme El Niño events in the last four or five decades than previously, and that would be consistent with model-based predictions that this century we will start to see more frequent extreme El Niño events,” Swain explained.
Mcphaden agrees and believes this year could provide more data to support that hypothesis. “If this event really turns out to be a very strong one, that would be unusual, because the last very strong event occurred only 10 years ago,” he said. “The typical return rate for really strong events is 15 to 20 years.”
If super El Niños are becoming more common in a warming world, the reason why may be related to their role in the global climate system. This stage of the ENSO cycle essentially serves as a stored-energy release mechanism, belching excess heat out of the tropical Pacific. But as the global atmosphere warms, the ocean absorbs more heat, thus releasing more during an El Niño year.
This points to a potential feedback loop. If global warming increases the occurrence of strong El Niño events, those events can, in turn, amplify the near-term impacts of global warming.
It will be a long time before climatologists have the necessary records to fully investigate that relationship, but what is clear is that El Niño and human-driven climate change are not isolated forces. Untangling them will be critical to understanding our warming world.
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