Overview
- A Stanford‑led paper published in PNAS in July 2026 presents laboratory evidence that ocean warming combined with large‑scale deoxygenation best explains the Permian–Triassic marine die‑off.
- Scientists measured how oxygen consumption rose with temperature in modern species that stand in for pre‑ and post‑extinction groups to test physiological vulnerability.
- The experiments show slow, sessile, low‑metabolism animals lost oxygen tolerance fastest as water warmed, which explains why brachiopods and crinoids nearly vanished.
- More active groups such as mollusks, snails and fishes tolerated temperature‑linked oxygen stress better because they have faster, more efficient respiratory systems.
- The authors tie the ocean changes to massive volcanic CO₂ and methane release, plan follow‑up tests that combine warming, acidification and deoxygenation, and warn the findings offer a cautionary parallel to modern human‑driven warming.