A powerful El Niño has developed months ahead of schedule, and multiple climate scientists say it could end up surpassing every previous event on record, according to recent reporting from CBC News and The Economist. For insurers globally, the timing adds new urgency to how catastrophe models account for both near-term weather volatility and longer-term warming trends that current models may be underestimating.
Ocean temperatures in the Niño 3.4 region of the Pacific, the benchmark zone used to measure El Niño strength, were already running close to 2°C above average in mid-July. That's well above the 0.5°C threshold typically used to declare an El Niño event, and notably, the event hasn't even peaked yet. Most forecasts point to a peak sometime between October and December.
Zeke Hausfather, a climate scientist with Berkeley Earth cited in the CBC report, said current conditions are already brushing up against "super El Niño" territory, a term used informally for the most extreme events. He noted that some forecasting models are now pointing to a possible peak of around 3.6°C above average, which would substantially exceed the previous record set during the 2015-2016 El Niño, when the anomaly reached roughly 2.75°C. A comparable event is believed to have occurred in 1877-78.
What's notable to scientists isn't just the potential scale of the event, but the speed of the transition. According to Nat Johnson, a meteorologist with NOAA's geophysical fluid dynamics laboratory, last winter's conditions were still consistent with a La Niña, the cooler counterpart phase in the same Pacific oscillation cycle. Moving from that baseline to a potentially record-setting El Niño within roughly a year is an unusually rapid shift, and researchers say it isn't yet clear why this year's swing has been so pronounced, or what role, if any, climate change is playing in it.
The practical concerns for insurers span several fronts. In tropical regions, forecasters are watching food security risk tied to El Niño-driven drought, an exposure that carries knock-on effects for agricultural lines and broader economic stability in affected markets. In Canada and other higher-latitude regions, the pattern typically brings milder but drier winters, conditions that raise concern for wildfire activity heading into the following spring and summer. Given how active recent wildfire seasons have already been across North America, an added layer of dryness from El Niño is being flagged as a compounding risk factor rather than an isolated one.
Underlying all of this is a separate, longer-running scientific puzzle that The Economist detailed in a recent feature: satellite and ocean-based measurements show that Earth's energy imbalance, the gap between the energy the planet absorbs from the sun and the energy it radiates back into space, has more than doubled since 2000. That imbalance is being tracked through NASA's CERES satellite program and corroborated independently by the Argo network of ocean-monitoring floats, which shows a consistent pattern of excess heat accumulating primarily in the upper ocean.
The concerning part for climate scientists isn't only the size of that imbalance, but that current climate models, including those used in the IPCC's own assessments, aren't able to fully reproduce it. Researchers pointed to two likely contributing factors: a decline in reflective sulphate aerosols due to tighter regulations on emissions from ships and power plants, and changes in cloud behaviour and sea ice that reduce how much sunlight the planet reflects. Both effects reduce Earth's albedo, meaning less energy bounces back into space and more gets absorbed.
Some researchers argue that if models are underestimating the size of this imbalance, they may also be underestimating "climate sensitivity," the amount of warming expected for a given increase in atmospheric forcing. One recent study concluded that current best-estimate sensitivity figures used by the IPCC may represent the low end of what's scientifically plausible, rather than a central, well-supported figure. If that turns out to be accurate, near-term global warming could progress faster than current consensus projections suggest.
Taken together, the two developments point toward the same broad conclusion for insurers across markets: near-term catastrophe risk tied to this year's El Niño may be amplified by longer-term warming trends that aren't yet fully captured in the models underpinning today's risk pricing and reserving. Neither article suggests an immediate change to how insurers should model risk, but both underscore a widening gap between observed physical conditions and the assumptions embedded in existing climate and catastrophe models, a gap that researchers say deserves closer scrutiny as this El Niño season develops.
