TWELVE REGIONS, ONE RANKING, NO CONTEST

Each bar is how much warmer the previous decade was, compared to the 1980s, for one region of the planet. Six are land, six are ocean. They start dead level in 1988 and then they separate.

The rule shows up almost immediately: land warms faster. By the end the land regions average 1.66 degrees above the 1980s, the ocean regions 0.90. Land is warming about 1.85 times faster than the sea. Land has no depth to hide the heat in and no evaporating surface to spend it on, so what arrives stays near the ground.

Then look at who is in second place. The Arctic Ocean, at 2.36, above every land region on Earth except the Arctic's own land. That is the exception that proves the rule, because that ocean has been losing the thing that insulated it. Sea ice reflects sunlight and caps the water underneath; take it away and the ocean absorbs the sun directly and then gives its heat straight to the air above. The surface there has not just warmed, it has changed its nature.

Third place is Europe, at 2.13, and that is not an artifact. Europe is the fastest warming continent on the planet.

And look at the bottom, because it is just as physical. The Southern Ocean and the Tropical Pacific come last, at 0.28 and 0.32. Not because they are not absorbing heat, but because they get rid of it downwards: the Southern Ocean is where the deep ocean ventilates and carries heat away from the surface, and the tropical Pacific is fed by upwelling of cold water from below. Those two bars are the planet's heat sink doing its job.

Three honest notes. This is air temperature everywhere, over land and over sea, so the marine bars are not SST: comparing two different quantities in one ranking would mean nothing. Each region's zero is its own 1980s average, which is what lets the Arctic and Africa share an axis. And every bar is a decade average, so it understates right now: the last decade sits 2.50 above the 1980s in the Arctic, and the most recent single years are higher still.

Data: ERA5 reanalysis, ECMWF. 2 m air temperature, 1979 to 2025, area weighted, land and sea separated with the ERA5 land-sea mask.