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

A leading scientist forecasts that 2026 will become the hottest year on record, driven by climate change and a significant El Niño event that will elevate temperatures further.

The current record was set in 2024, when global temperatures surpassed 1.5°C above the pre-industrial average for the first time.

El Niño is expected to begin in the latter half of this year, a natural climate phase that involves warm water spreading across the equatorial Pacific Ocean, thereby warming the entire planet. Some projections suggest it could develop into a “super El Niño,” potentially the most intense ever. Many anticipate this will result in a new global temperature record in 2027, as the full impact of El Niño is realized.

However, James Hansen of Columbia University in New York, known for his 1988 testimony to the US Congress about human-induced global warming, and his colleagues have argued in a blog post that the record will be broken as early as 2026. They added, “Of course, 2027 will be still hotter.”

Currently, temperatures are being moderated by La Niña, El Niño’s cooler counterpart. In the first three months of 2026, temperatures averaged 0.1°C cooler than the same period in 2024. The remainder of the year would need to be significantly warmer for 2026 to eclipse 2024.

Zeke Hausfather from Berkeley Earth in California estimated in Carbon Brief that based on the initial three months, 2026 will be 1.47°C above the pre-industrial average, making it the second warmest year recorded.

Yet, Hansen and his team believe this is an underestimation. While many scientists agree that global warming is accelerating, mainly due to reduced air pollution that previously blocked sunlight, Hansen argues that the warming rate is greater than what climate models indicate.

They point out that sea surface temperatures, less influenced by weather changes, indicate the world is now 0.17°C warmer than in 2023, when the 2023-24 El Niño began. This difference is greater than in 2024, which was only 0.11°C warmer than 2023.

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

However, not all scientists agree. The Met Office in the UK forecasted that next year would be 1.46°C above the pre-industrial average, with a range from 1.34°C to 1.58°C. Adam Scaife from the Met Office notes that it’s premature to predict 2026 will surpass the 1.55°C recorded in 2024.

“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 continues to warm and El Niño becomes more likely, the probability of record global temperatures also increases, but forecasts still show a wide range 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 that 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.

Scaife acknowledges Hansen’s concern that global warming may be accelerating faster than projected, as this would imply the CO2 emitted is warming the Earth more than anticipated. “If climate sensitivity’s higher than people think… that will affect climate change in the future,” he says.

Regardless of the precise global temperature, the world is likely to experience even more severe extreme weather as El Niño intensifies. Regions such as Australia, South-East Asia, central and southern Africa, India, and the Amazon rainforest could face increased risks 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,” notes one scientist. “Those two things are likely to give us unprecedented events later this year.”