Soru

### Carbon Cycle Disruption at the PETM

Approximately $56\text{ million}$ years ago, Earth experienced the Paleocene-Eocene Thermal Maximum (PETM), a period of rapid global warming accompanied by a major carbon cycle disruption. Three scientists propose different hypotheses regarding the primary source of the carbon release.

Scientist 1
The PETM was triggered by the sudden dissociation of methane hydrates (methane gas trapped in ice-like cages within marine sediments). Rapid initial warming, caused by orbital cycles, warmed the deep ocean waters. Once a critical temperature threshold was reached, these marine sediments destabilized, releasing vast amounts of methane ($CH_4$) into the ocean and atmosphere. Because methane is a potent greenhouse gas that rapidly oxidizes to carbon dioxide ($CO_2$) in the atmosphere, this release caused runaway global warming.

Scientist 2
The carbon release was caused by intense volcanic activity associated with the opening of the North Atlantic Ocean. Large-scale magma eruptions intruded into organic-rich sedimentary basins, heating coal and shale deposits. This thermal metamorphism released massive volumes of thermogenic methane ($CH_4$) and carbon dioxide ($CO_2$) directly into the atmosphere through hydrothermal vents. This volcanic venting occurred in a series of pulses, driving the global temperature increases.

Scientist 3
The carbon source was the widespread combustion and decay of terrestrial organic matter, specifically peatlands and permafrost. A prolonged drought period, initiated by orbital forcing, dried out expansive high-latitude peatlands. This made them highly susceptible to wildfire and rapid aerobic decomposition. The burning and decay of this organic matter released massive quantities of $CO_2$ directly into the atmosphere, bypassing the marine reservoir entirely and causing the observed warming.

Based on the passage, which of the following statements best describes the core claim of Scientist 2 regarding the primary source and pathway of carbon released during the PETM?