2026 will be the hottest year on record, leading scientist predicts

A prominent scientist has predicted 2026 will be the hottest year on record, thanks to both climate change and a powerful El Niño effect that will raise temperatures further.

The record is held by 2024, when global temperatures exceeded 1.5°C above the pre-industrial average for the first time.

The second half of this year will almost certainly see the start of El Niño, a natural climate phase when warm water expands across the equatorial Pacific Ocean, heating the entire planet. Some models project it will be a “super El Niño”, and perhaps the strongest ever. Many believe this will set a new global temperature record in 2027, when the full force of the El Niño is felt.

But James Hansen at Columbia University in New York, who famously told the US Congress in 1988 that humans were heating Earth, and his colleagues have now argued in a blog post that the record will be broken already in 2026. “Of course, 2027 will be still hotter,” they added.

Temperatures are currently being suppressed by La Niña, the planet-cooling counterpart of El Niño. The first three months of 2026 were about 0.1°C cooler than the first three months of 2024, on average. The rest of the year would have to be far hotter for 2026 to surpass 2024.

Based on the average effect of the first three months on the yearly temperature, Zeke Hausfather at Berkeley Earth in California projected in Carbon Brief that 2026 would be 1.47°C above the pre-industrial average, making it the second-warmest on record.

But Hansen and his colleagues say this is likely to be an underestimate. While scientists largely agree that global warming is accelerating, mainly because humanity has reduced air pollution that was blocking out sunlight, Hansen has argued the warming rate is even higher than climate models show.

In their post, they note that sea surface temperatures, which are less affected by fluctuations in the weather, suggest the world is now 0.17°C warmer than in 2023, when the 2023-24 El Niño developed. This is a bigger difference than in 2024, when the globe was only 0.11°C warmer than it was in 2023.

“That margin is wide enough that we are willing to make the prediction that 2026 will be the warmest year”, they wrote.

Other scientists aren’t so sure. While the annual forecast in December from the Met Office, the UK’s weather service, projected the next year would be 1.46°C above the pre-industrial average, it gave a range from 1.34°C to 1.58°C. It’s still premature to predict 2026 will beat the 1.55°C recorded in 2024, says Adam Scaife at the Met Office.

“There is uncertainty on these timescales, which means that the best thing you can do is to give a probability,” says Scaife. “Nobody can be 100 per cent confident.”

As the equatorial Pacific has continued to warm and El Niño has become more likely, record global temperatures have also become more likely, but forecasts still show a sweep of possible outcomes, according to John Kennedy at the World Meteorological Organization. “Hansen’s forecast is more definitive, but it is just one method out of a range that are out there,” he says.

In a blog post on 30 April, Hausfather calculated 2026 has a 26 per cent chance of being the hottest year on record and a 56 per cent chance of being the second hottest.

But Scaife says Hansen is right to worry that the rate of global warming may be faster than projected, because that would suggest the CO2 emitted into the atmosphere is warming Earth more than expected. “If climate sensitivity’s higher than people think… that will affect climate change in the future,” he says.

Regardless of the exact global temperature, the world is likely to suffer even worse extreme weather as El Niño starts to bite. Places like Australia and South-East Asia, central and southern Africa, India and the Amazon rainforest will face the risk of heatwaves, drought and wildfires.

“What we all agree about is that the El Niño is going to be on top of an unprecedented level of global warming,” says. “Those two things are likely to give us unprecedented events later this year.”