Mountain Growth Spurts Tracked Earth's Oxygen Surges

Earth's tallest mountains are a late invention, and their arrival may explain why complex life exists at all. A study published in Science Advances on November 13, 2026, by Matthijs Smit of the University of British Columbia and colleagues finds that mountain ranges grew in two distinct spurts over the past 3 billion years, and that each spurt coincides with one of the planet's great oxidation events, the episodes that filled the air with breathable oxygen.

The team read the record in metamorphic rocks, the rocks that colliding tectonic plates push deep underground and later return to the surface. Those rocks preserve how thick the crust beneath a mountain belt became, and thickness is what lets a range stand tall. Across 3 billion years, the maximum crustal thickness in mountain belts jumped first from 30 to 60 kilometers (19 to 37 miles) and later to almost 90 kilometers (56 miles).

The timing is the argument. By the first global oxidation event 2.2 billion years ago, mountains had grown from near sea level to about half as high as today's Himalayas. The second growth spurt arrived with the second major oxidation event around 700 million years ago, thrusting ranges to enormous heights. Smit's group ties the change to a cooling planet: as Earth cooled, the process that builds mountains changed, and ranges could grow taller.

Height matters because mountains are nutrient machines. Before 3 billion years ago, elements such as phosphorus, an essential ingredient for life, stayed locked in the crust and the oceans were nutrient-starved. Taller ranges weather and erode on a far larger scale, washing those nutrients into the sea. Fed properly, photosynthetic life could flourish, and photosynthesis is what raised atmospheric oxygen.

"Changes that occurred deep in the Earth ultimately gave rise to much taller mountains over time, which may have made our planet habitable by providing the nutrients needed for life to form and flourish," Smit said. Co-author Douwe van Hinsbergen of Utrecht University added that the first spurt may have produced land on a large scale for the first time, while the second drove ranges to the heights that preceded the bloom of complex animals.

Today's extremes show how far the process has run. Everest, K2 and Kangchenjunga, the three highest peaks on Earth, stand almost 9 kilometers (5.6 miles) above sea level on crust up to 80 kilometers thick, about double the thickness of most other continents. Ellen Kooijman of the Swedish Museum of Natural History, a co-author, called it likely no coincidence that life diversified in step with the two spurts. The claim is a correlation built from rock physics, not a filmed cause, and the paper frames it that way. But it hands the origin of complex life a new suspect: the slow thickening of the ground under colliding continents.

The method is worth stating plainly, because it's what makes the claim testable. Metamorphic rocks record the pressures they endured while buried, and pressure translates into depth, and depth into the thickness of the crust that once sat above them. By dating those rocks across three billion years of mountain belts, the team could chart how the ceiling on crustal thickness rose in steps rather than smoothly. A smooth rise would have made the oxygen timing a coincidence. Two steps, landing on the two oxidation events, are what turned a chart into an argument.