Global warming is poised to accelerate in 2023 and 2024

Animation showing the change in global mean surface temperature from the average compared to 1951-1980. Image: NASA GISS.

Believe it or not, average global surface temperatures have actually been relatively cool over the past three years – but that’s about to change.

Why it matters: Temperatures are expected to rise this year — and 2024 could set a new global record.

The big picture: A rare La Niña “triple dip” in the tropical Pacific Ocean kept temperatures in check in 2022, with the year ranking as the fifth warmest since instrumental records began.

La Niña events are characterized by cooler than average waters in the equatorial tropical Pacific and tend to put a cap on global temperatures. But 2022 still finished as the fifth warmest year on record according to NASA and the Copernicus Climate Change Service. And if the phenomenon disappears, as forecasts increasingly indicate, global temperatures are likely to rise this year and even more next year. If an El Niño event — characterized by warmer-than-average ocean temperatures — sets in across the tropical Pacific, 2023 could even meet or come close to reaching a record high.

What they’re saying: “I predict about a 15% chance of a new record in 2023. And if we’re in an El Niño until the end of 2023, a near certainty of a new record in 2024,” Gavin Schmidt, who directs NASA’s Goddard Institute for Space Studies in New York, told Axios via email.

Zoom in: According to NASA, the warmest year on record occurred in 2020 and 2016, the latter of which occurred when a major El Niño was underway. This has led some climate change skeptics to claim that global warming stopped in 2016.

What’s next: This year looks milder than recent years. It has a good chance of at least entering the first five years, if not the three warmest years, depending on how a transition to an El Niño plays out.

Then, 2024 is most likely to set a new record, scientists told Axios. This is partly because there is a lag in the atmosphere’s response to El Niño.

Threat level: The UK Met Office predicts that global average temperatures in 2023 will be at least 1.2°C (2.16°F) above the pre-industrial average. Keep in mind that the Paris Agreement tries to limit warming to 1.5°C.

If warming exceeds this goal, the studies show, the likelihood of potentially devastating consequences of climate change will increase, such as greater melting of polar ice sheets and the loss of tropical coral reefs. Zeke Hausfather, head of climate research at payments company Stripe, said 2023 looks warmer than recent years, but determining exactly how much is difficult at this point.”Given the lags in the surface temperature response , a transition to El Niño conditions in the second half of 2023 would have more impact in 2024,” he said via email.