ENVS 2160 Lecture Notes - Lecture 30: Atmospheric Circulation, Cenozoic, Heinrich Event
22 Jun 2016
School
Department
Course
Professor
Document Summary
Abrupt climate change transition of the climate system into a different state (temp, rainfall, etc. ) on a time-scale that"s faster than the responsible forcing. Change of climate system that"s faster than the adaptation time of society and/or ecosystems. Recorded in marine sediments and gisp/grip ice cores. Starts with abrupt warming, followed by gradual cooling. Abrupt warming (change) occurs in 10-100yrs and lasts several 1000yrs. Temperature changes 6-10c, on top of the cooler conditions of glacial periods (~15c cooler) Longer-term cycles which consist of bundles of d-o events. Characterized by abrupt warming following one of the d-o cold periods, during which there was a. Ended with a 8c temperature rise over 10yrs. The last d-i cycle before the current warm holocene. Determining causes of climate variations is tricky because: cause and effect relationships hard to establish. E. g. is the rise in co2 a cause of deglaciation or an effect of it: feedback processes chicken-egg dilemma.
