Palaeoclimate sensitivity to CO2 and insolation

摘要: The current Quaternary Ice Age is characterized by multiple switches of the global climate between glacials and interglacials. Louvain-la-Neuve two-dimensional (altitude-latitude) model (LLN 2-D model) has been used to simulate long-term variations Northern Hemisphere climate. forced both CO2 insolation for each day latitude. period analyzed here from 200 ka BP AP. provides a total continental ice volume, which compares relatively well with SPECMAP oxygen-isotope record, size extent individual sheets being in fair agreement their geological reconstructions. Seven simulations were done quantify relative contribution forcings albedo water-vapor temperature feedbacks last glacial maximum (LGM) cooling. This LGM cooling 4.5 degrees C would be due alone 20.8%, feedback 40%, water vapor 38.6%. If we consider low concentration as only forcing, but allow change, 33% are explained.