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The end-Permian mass extinction (EPME) is associated with the loss of approximately 80–90 % marine species and 70 % terrestrial taxa. Massive greenhouse gas emissions from activities of the Siberian Traps Large Igneous Province (ST-LIP) and arc volcanisms are thought to be the trigger of the EPME. Global temperatures rose significantly following the EPME, and such extreme warmth persisted into the Early Triassic, which may have led to enhanced silicate weathering, and increased river runoff and sediment accumulation rate. However, ecosystem recovery was delayed by at least five million years after the EPME. One leading hypothesis attributes this protracted recovery to sustained atmospheric CO₂ accumulation, resulting from volcanic emissions from the ST-LIP that overwhelmed the normal Earth surface carbon cycle. To evaluate this, we synthesize geochemical and sedimentological records of continental weathering across the Permian–Triassic (PT) transition, drawing on a suite of proxies including major elements-based proxies, strontium (87/86Sr and δ88/86Sr), osmium (187Os/188Os), lithium (δ7Li), magnesium (δ26Mg) and calcium (δ44Ca) isotopes. We highlight the strengths and limitations of each proxy and assess how chemical and physical weathering may have responded to the environmental perturbations across the PT transition. Collectively, these records can help test the hypothesis that the silicate weathering feedback were insufficient to counteract elevated CO2 levels, thereby failing to stabilize Earth’s climate during the prolonged Early Triassic warmth. 

The largest mass extinction event is associated with changes in degassing style of the Siberian Traps volcanism. 

The end-Permian mass extinction event (∼252 Mya) is associated with one of the largest global carbon cycle perturbations in the Phanerozoic and is thought to be triggered by the Siberian Traps volcanism. Sizable carbon isotope excursions (CIEs) have been found at numerous sites around the world, suggesting massive quantities of 13 C-depleted CO 2 input into the ocean and atmosphere system. The exact magnitude and cause of the CIEs, the pace of CO 2 emission, and the total quantity of CO 2 , however, remain poorly known. Here, we quantify the CO 2 emission in an Earth system model based on new compound-specific carbon isotope records from the Finnmark Platform and an astronomically tuned age model. By quantitatively comparing the modeled surface ocean pH and boron isotope pH proxy, a massive (∼36,000 Gt C) and rapid emission (∼5 Gt C yr −1 ) of largely volcanic CO 2 source (∼−15%) is necessary to drive the observed pattern of CIE, the abrupt decline in surface ocean pH, and the extreme global temperature increase. This suggests that the massive amount of greenhouse gases may have pushed the Earth system toward a critical tipping point, beyond which extreme changes in ocean pH and temperature led to irreversible mass extinction. The comparatively amplified CIE observed in higher plant leaf waxes suggests that the surface waters of the Finnmark Platform were likely out of equilibrium with the initial massive centennial-scale release of carbon from the massive Siberian Traps volcanism, supporting the rapidity of carbon injection. Our modeling work reveals that carbon emission pulses are accompanied by organic carbon burial, facilitated by widespread ocean anoxia.