2003/01/31 by Gavin A. Schmidt, Drew Shindell · 1 citation
Environmental Science · Engineering · #Methane Hydrates and Related Phenomena #Atmospheric and Environmental Gas Dynamics #Hydrocarbon exploration and reservoir analysis
paper · doi:10.1029/2002pa000757
openalex publication_date 2003/01/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
The massive perturbation to global climate and the carbon cycle during the Paleocene/Eocene Thermal Maximum (PETM) (approx. 55.5 Ma) may have been forced by a catastrophic release of methane gas (CH 4 ) from hydrate deposits on the continental slope. We investigate whether reported PETM paleotemperature and paleo‐CO 2 proxies are consistent with this hypothesis by considering the impact of large increases in CH 4 emissions to the atmosphere. Significant effects on atmospheric chemistry and CH 4 lifetime are seen for a range of plausible emission rates (1500 Gt carbon over 500–20,000 years). The resulting peak anomalous radiative forcing is 1.5–13.3 W/m 2 depending on the emission scenario. The scenarios most closely matched to the PETM carbon isotope excursion have peak forcing of around 3 W/m 2 , which translates to peak temperature changes as a function of latitude that are a reasonable match to derived estimates. High CH 4 levels and enhanced stratospheric water vapor amounts persist for as long as do the emissions and are responsible for more of the peak radiative forcing than CO 2 levels, although results are sensitive to the background climate state and base CH 4 concentration.