The past three years have been the world’s hottest on record by far, with 2025 almost tied with 2023 for second place. With that energy came extreme weather, from flash flooding to powerful hurricanes and severe droughts. Yet, by most indicators, the planet should have been cooler in 2025 than it was.
So, what happened, and what does that say about the year ahead?
As an earth and environmental scientist, I study influences that affect global temperatures year to year, such as El Niño, wildfires and solar cycles. Some make Earth hotter. Some make it cooler. And one particularly unhealthy influence has been quietly hiding a large amount of global warming – until now.
The past three years have been the warmest on record. The chart compiled by the European Union’s Copernicus Climate Change Service shows the comparison to preindustrial-era temperatures in the second half of the 1800s. C3S/ECMWF
Factors that made 2025 cooler than 2024
