Mass Extinctions & Climate
The history of life on Earth has been punctuated by catastrophic die-offs — each one driven by, or driving, extreme climate disruption. Five events wiped out more than 75% of all species. Every one involved rapid temperature change, ocean chemistry shifts, or both.
Global Temperature & Extinction Events — 550 Ma to Present
Temperature anomaly from geochemical proxies (δ¹⁸O, Mg/Ca, GEOCARB) · extinction intensity shown as vertical bands · width proportional to duration
Extinction Severity — Species Lost
Estimated % of all marine species eliminated at each event
Temperature Change at Each Event
Rapid ΔT associated with the extinction horizon (global mean estimate)
The Big Five & Notable Events
Common Climate Mechanisms
Recurring pathways by which climate change kills species en masse
- Large Igneous Province (LIP) volcanism — Eruption of flood basalts over millions of km² injects SO₂ (short-term cooling) then CO₂ (long-term warming). Drives ocean anoxia, acidification, and temperature swings that collapse marine ecosystems. Implicated in End-Permian, End-Triassic, and contributed to Late Devonian.
- Rapid warming → ocean anoxia — Warmer oceans hold less dissolved oxygen. Stratification prevents deep-water reoxygenation. Black shales (anoxic sediments) are the geological fingerprint. The End-Permian ocean became almost entirely anoxic, making much of the seafloor uninhabitable for centuries.
- Glaciation → sea-level fall — Rapid ice sheet growth locks water on land, dropping sea level by tens of metres. Shallow continental shelves — home to the vast majority of marine life — are exposed and desiccated. Drove the End-Ordovician extinction. Sea-level fall also fragments habitats and eliminates carbonate reef ecosystems.
- CO₂ acidification — Rapid CO₂ injection (volcanic or impact) lowers ocean pH, dissolving calcite and aragonite shells. Organisms that build shells — corals, molluscs, forams, echinoderms — face direct chemical dissolution. The End-Permian and PETM both show carbonate dissolution horizons in the sedimentary record.
- Impact winter → collapse of photosynthesis — A large impactor throws dust, soot, and sulfate aerosols into the stratosphere, blocking sunlight for months to years. Plants and phytoplankton die → the food web collapses from the base upward. The K-Pg Chicxulub impact is the only confirmed example in the Big Five, but the mechanism is well-understood from nuclear winter models.
Recovery Times
How long it took ecosystems to rebuild diversity after each event