![]() Within this canonical framework, it is expected that rapid CO 2 release will be met by accelerated rates of silicate weathering and thus enhanced carbon removal, stabilizing and restoring temperatures on 10 5 yr timescale 14, 15, 24 (e.g., Paleocene–Eocene event 3, 25). The result is a stabilizing feedback that is widely viewed to give rise to the persistence of clement climates on Earth 14, 20. This reaction proceeds more rapidly with higher global temperatures and associated intensification of the hydrologic cycle. The neutralization of CO 2 through the weathering of primary silicate materials, when tied to the precipitation of carbonate (CaCO 3) and chert (SiO 2), sequesters carbon from the ocean–atmosphere system 23. Long-term climate on Earth is regulated by the coupled global carbon and silica cycles 14, 15, 16, 17, 18, 19, 20, 21, 22. Of particular interest are the records of extreme temperature that cannot be easily explained with the standard view of climate regulation during hyperthermals. Despite the growing consensus for a causal link between the establishment of warm and anoxic oceans and the widespread loss of marine biodiversity 4, 12, 13, basic aspects of the end-Permian crisis remain enigmatic. An estimated 85–95% of all marine animal species went extinct across the latest Permian/Early Triassic transition-making it the most severe extinction event in Earth’s history 1, 5, 13. A rapid temperature rise of >10 ☌ 2, 10, acidification 11, and marine O 2 decline 12, 13 drove a massive loss in biodiversity and a major shift in marine ecosystem structure 5. This is the only known climate perturbation where carbon release rates and the initial pace of warming may have been comparable to modern rates 6, 7, 8, 9. Global warming at the end-Permian initiated the most adverse and extended environmental crisis in the Phanerozoic 1, 2, 3, 4, 5. This refined view of the carbon-silica cycle highlights that the ecological success of siliceous organisms exerts a potentially significant influence on Earth’s climate regime. ![]() While solid-Earth degassing may have acted as a trigger, subsequent biotic feedbacks likely exacerbated and prolonged the environmental crisis. Here, we propose that the development of widespread marine anoxia and Si-rich conditions, linked to the collapse of the biological silica factory, warming, and increased weathering, was capable of trapping Earth’s system within a hyperthermal by enhancing ocean-atmosphere CO 2 recycling via authigenic clay formation. This protracted recovery defies our current understanding of climate regulation via the silicate weathering feedback, and hints at a fundamentally altered carbon and silica cycle. In the wake of rapid CO 2 release tied to the emplacement of the Siberian Traps, elevated temperatures were maintained for over five million years during the end-Permian biotic crisis. ![]()
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