By Cliff Potts, CSO, and Editor-in-Chief of WPS News

Baybay City, Leyte, Philippines — May 26, 2026

When the Permian–Triassic extinction event reached the continents, the outcome was already constrained by what had happened in the seas. With oceans warming, oxygen-poor, and in places toxic, Earth’s atmosphere had become unstable. What followed on land was not a mirror of oceanic collapse, but its consequence.

Life on land did not simply die. It was stripped of the conditions that made survival possible.

A Rapid Rise in Heat

Volcanic gases released during the Siberian Traps eruptions accumulated over long periods. Carbon dioxide drove sustained warming that reshaped continental climates. Temperature increases of several degrees were enough to push many regions beyond the tolerance limits of plants and animals adapted to earlier conditions.

Heat stress affected physiology directly. Large-bodied animals struggled to regulate temperature. Plants lost moisture faster than they could replace it. Seasonal cycles became erratic, undermining reproduction and food availability.

Unlike oceans, land offered some refuges—but far fewer than expected.

Acid Rain and Soil Failure

Sulfur dioxide released during prolonged volcanism combined with atmospheric moisture to form acid rain. This precipitation did not simply damage leaves or bark. It altered soils at a chemical level.

Nutrients leached away. Root systems weakened. Forests that had stabilized ecosystems for millions of years began to thin and then collapse. As plant cover disappeared, erosion increased, further degrading habitats.

Once soils failed, recovery became unlikely even if temperatures stabilized. Land ecosystems depend on soil chemistry as much as climate.

Atmospheric Instability

The atmosphere itself became hostile. In addition to carbon dioxide and sulfur compounds, volcanic activity released halogens and other trace gases. These likely contributed to ozone depletion, increasing ultraviolet radiation at the surface.

Higher UV exposure stresses plants, damages DNA, and reduces photosynthetic efficiency. For animals already weakened by heat and food shortages, this additional pressure proved lethal.

The land was not facing a single threat. It was facing many at once.

Why Distance Did Not Save Anyone

One of the defining features of the Great Dying is that even regions far from volcanic activity experienced collapse. Continents on the opposite side of Pangaea show evidence of forest loss and vertebrate extinction.

This was not because lava reached them. It was because the atmosphere connects the planet. Heat, gases, and precipitation patterns do not respect geography. Once the atmospheric system shifted, no landmass remained isolated.

This explains why extinction on land was nearly global despite localized eruptions.

Survivors in the Margins

As on the oceans, survival favored organisms that were small, adaptable, and tolerant of harsh conditions. Burrowing animals found shelter from heat and radiation. Opportunistic feeders survived where specialists starved.

Large herbivores and apex predators disappeared in disproportionate numbers. Complex food webs collapsed into simpler, temporary systems dominated by generalists.

The land did not empty completely—but it lost its structure.

The End of an Old World

By the height of the extinction, forests had vanished from many regions. River systems changed as vegetation loss altered runoff patterns. What remained was a hotter, harsher planet with limited capacity to support complex life.

The Great Dying on land was not a sudden apocalypse. It was a drawn-out failure of climate, soil, and atmosphere acting together.

The next essay will examine why extinction extended even into regions untouched by lava—and how planetary feedback loops ensured that nowhere remained safe.

For more social commentary, please see Occupy 2.5 at https://Occupy25.com

This essay will be archived as part of the ongoing WPS News Monthly Brief Series available through Amazon.

References

Beerling, D. J., & Berner, R. A. (2002). Biogeochemical constraints on the end-Permian mass extinction. Proceedings of the National Academy of Sciences, 99(7), 4172–4177.
Retallack, G. J. (1995). Permian–Triassic life crisis on land. Science, 267(5194), 77–80.
Self, S., Thordarson, T., & Widdowson, M. (2005). Gas fluxes from flood basalt eruptions. Earth and Planetary Science Letters, 235(1–2), 17–30.

Discover more from WPS News

Subscribe to get the latest posts sent to your email.