The planet just lived through its two hottest years on record, back to back. Now, as Pacific Ocean conditions shift in ways that have climate scientists on alert, a growing body of research suggests the next major El Nino could shatter those records by a margin that dwarfs anything in the modern temperature archive, potentially pushing global heat to levels the Earth has not experienced since before systematic measurements began in 1850.
Three independent agencies confirmed in early 2025 that 2024 was the warmest year in at least 175 years of global temperature tracking, edging past 2023 by a slim but consistent margin. Preliminary data released through early 2026 shows the planet has remained near that elevated baseline. And scientists studying tropical Pacific sea surface temperatures say the ingredients for a powerful El Nino are accumulating beneath the surface, raising the prospect of another temperature surge in the months ahead.
“We are loading the dice,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, in a January 2025 briefing on the record. “The background warming from greenhouse gases means every El Nino now starts from a higher baseline than the last one.”
What the temperature record actually shows
NASA, NOAA, and the UK Met Office each reached the same conclusion about 2024 using separate datasets and methods. NOAA’s GlobalTemp series, which covers 1850 to the present, ranked 2024 as the warmest year in its record, beating 2023 by 0.18 degrees Fahrenheit (0.10 degrees Celsius). That margin is narrow in absolute terms, but its consistency across all three agencies makes it difficult to attribute to any single measurement quirk.
The UK Met Office placed 2024 at 1.53 degrees Celsius above the 1850-to-1900 pre-industrial baseline, with an uncertainty range of plus or minus 0.08 degrees Celsius, using its HadCRUT5 dataset. That figure sits above the 1.5-degree Celsius threshold that international climate negotiations have long treated as a critical guardrail, though scientists are careful to distinguish a single year from the sustained multi-decade average the Paris Agreement targets.
The convergence matters because each agency relies on different raw inputs and statistical techniques. NOAA’s GlobalTemp incorporates the Extended Reconstructed Sea Surface Temperature dataset (ERSSTv5) alongside land station records from its global surface temperature product. The Met Office’s HadCRUT5 uses a separate gridded approach. NASA’s GISTEMP v4 applies its own spatial interpolation methods to fill data gaps, particularly in the Arctic. When all three point in the same direction, the signal is robust.
Beyond the global average, the agencies reported similar patterns in regional extremes. Land areas warmed faster than oceans. Marine heatwaves battered large stretches of the North Atlantic and eastern Pacific, compounding stress on coral reefs and fisheries. High northern latitudes saw especially sharp anomalies, consistent with the well-documented pattern of Arctic amplification.
Why a super El Nino would be different
El Nino events work by redistributing vast quantities of heat from the tropical Pacific into the atmosphere, temporarily raising global average temperatures. The 2023-to-2024 El Nino contributed to the record just broken, but it was a moderate event by historical standards. A “super” El Nino, the informal term scientists apply to episodes when sea surface temperature anomalies in the central and eastern Pacific exceed 2.0 degrees Celsius above average for sustained periods, would inject considerably more energy into the climate system.
The world has seen two such events in recent decades: 1997-to-1998 and 2015-to-2016. Both left deep marks. The 1997-98 event triggered catastrophic flooding across Peru and Ecuador, severe drought in Indonesia and Australia, and widespread coral bleaching across the tropics. Global temperatures spiked so sharply that 1998 held the annual record for more than a decade. The 2015-16 event was even stronger by some ocean metrics and contributed to 2016 becoming the hottest year on record at the time, a title it held until 2023 toppled it.
What makes the prospect of another super El Nino so consequential now is the baseline it would build on. The underlying global temperature has risen by more than 1.2 degrees Celsius since the late 19th century, driven primarily by the accumulation of carbon dioxide and other greenhouse gases. A super El Nino in the late 1990s operated on a baseline roughly 0.5 degrees Celsius lower than today’s. The same magnitude of Pacific warming, layered on top of the current baseline, would push the global average into territory that has no analog in the instrumental record.
“Think of it as a wave on a rising tide,” said Adam Scaife, head of long-range prediction at the UK Met Office, in a statement accompanying the 2024 record announcement. “Each El Nino now crests higher than the last because the ocean it sits on is warmer.”
What forecasters are watching in 2026
NOAA’s Climate Prediction Center and Columbia University’s International Research Institute for Climate and Society publish regular ENSO (El Nino-Southern Oscillation) outlooks that describe probabilistic ranges of outcomes rather than single dramatic scenarios. As of early 2026, those forecasts have flagged a transition from neutral or weak La Nina conditions toward a possible El Nino development later in the year, though the magnitude remains uncertain at this lead time.
Subsurface ocean temperatures in the equatorial Pacific are one of the key indicators scientists monitor. Warm water pooling below the surface can signal that an El Nino is building months before it appears at the surface. During the buildup to both the 1997 and 2015 super events, unusually large volumes of warm subsurface water, known as Kelvin waves, propagated eastward across the Pacific well in advance of the surface signature.
No forecast agency has labeled any developing event a “super El Nino” at this stage. The term is almost always applied after the fact, once sustained sea surface anomalies confirm the event’s strength. But the combination of a warming baseline, recent subsurface heat accumulation, and the historical pattern of strong El Ninos following extended La Nina periods has put the possibility squarely on the scientific radar.
The 1870s comparison, and its limits
Saying the planet is approaching temperatures not seen since the 1870s requires some unpacking. The instrumental record stretches back to 1850 in both the NOAA and HadCRUT5 datasets, but coverage in the earliest decades was sparse. Fewer weather stations existed, ocean measurements were limited to ship routes, and large parts of the Southern Hemisphere and polar regions went unmonitored.
What the early record does show is that the late 19th century was significantly cooler than today, sitting near the bottom of the industrial-era temperature range. The 1870s, in particular, included a period of relatively low volcanic and solar forcing that kept global temperatures subdued. The comparison in the headline is not that a super El Nino would return the planet to 1870s conditions, but rather that it could push temperatures so far above the modern baseline that the gap between current warmth and the pre-industrial era would reach levels unprecedented in the entire measurement period since the 1870s.
Paleoclimate reconstructions from ice cores, tree rings, and coral records can extend the temperature picture further back, but those proxies carry wider uncertainty bands than direct thermometer readings. Most reconstructions suggest that sustained global temperatures as warm as today’s have not occurred in at least 100,000 years, though short-lived spikes during past interglacial periods may have briefly matched or exceeded current levels in some regions.
What a record-breaking year would mean on the ground
For the billions of people living in regions sensitive to El Nino, the stakes are not abstract. Past super El Ninos have disrupted food production on multiple continents simultaneously. The 2015-16 event contributed to severe drought in southern Africa, where maize harvests dropped sharply, and to flooding in South America that displaced hundreds of thousands of people. In Southeast Asia, drought and fire consumed vast areas of Indonesian rainforest, sending plumes of smoke across the region and triggering a public health crisis.
A stronger event on a warmer baseline would amplify those risks. Warmer air holds more moisture, intensifying both the droughts in regions that dry out during El Nino and the rainfall in regions that get wetter. Coral reefs, already stressed by the back-to-back heat of 2023 and 2024, would face another round of mass bleaching with less time to recover. Agricultural systems operating closer to heat tolerance thresholds would have less margin for error.
Insurance and reinsurance companies have already flagged the scenario. Munich Re’s annual natural disaster review for 2024 noted that climate-related losses continue to trend upward, and that a strong El Nino year layered on top of the current warming trajectory would likely produce insured losses well above recent averages.
Where the science stands and what it cannot yet say
The verified facts are unusually clear: 2024 was the hottest year in the modern record, confirmed by three independent agencies using separate methods. The role of El Nino in amplifying global temperatures is well established in both observational data and physical theory. And the long-term warming trend, driven by greenhouse gas emissions, ensures that each new El Nino starts from a higher platform than the last.
What the science cannot yet specify is when the next super El Nino will arrive, how strong it will be, or exactly how high it will push global temperatures. Seasonal forecasts extend roughly nine months with useful skill; beyond that, the chaotic nature of the climate system limits precision. The difference between a moderate El Nino that nudges the record upward by a tenth of a degree and a super event that blows past it by half a degree is enormous in its consequences but impossible to predict with confidence more than a few months out.
What scientists can say with high confidence is that the trajectory points in one direction. Every decade since the 1970s has been warmer than the one before it. The ten hottest years on record have all occurred since 2010. And the physics of greenhouse gas forcing means the baseline will continue to rise as long as emissions remain near current levels. Against that backdrop, the question is not whether another record will fall, but how soon, and by how much.
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*This article was researched with the help of AI, with human editors creating the final content.
