Paleocene–Eocene Thermal Maximum
RAPID (IN GEOLOGICAL TERMS) GLOBAL WARMING, PROFOUND CHANGES IN ECOSYSTEMS, AND MAJOR PERTURBATIONS IN THE CARBON CYCLE WHICH STARTED ABOUT 55.0 MILLION YEARS AGO
Paleocene-Eocene thermal maximum; Palaeocene-Eocene Thermal Maximum; Paleocene-Eocene warming; Petm; Palaeocene-Eocene Temperature Maximum; PETM; Paleocene-Eocene Thermal Maximum; Palaeocene–Eocene Thermal Maximum; Paleocene eocene thermal maximum; Paleocene–Eocene thermal maximum; Initial Eocene Thermal Maximum; EECO
The Paleocene–Eocene thermal maximum (PETM), alternatively (ETM1), and formerly known as the "Initial Eocene" or "", was a time period with a more than 5–8 °C global average temperature rise across the event. This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs.