Quantifying the effect of vegetation dynamics on the climate of the Last Glacial Maximum

• Main Authors: Jahn, A., Claussen, M., Ganopolski, A., Brovkin, V.
• Other Authors: Potsdam Institute for Climate Impact Research (PIK), Institute of Physics, University of Potsdam = Universität Potsdam
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; taiga; Tundra
• Online Access: https://hal.science/hal-00298109; https://hal.science/hal-00298109/document; https://hal.science/hal-00298109/file/cpd-1-1-2005.pdf

International audience The importance of the biogeophysical atmosphere-vegetation feedback in comparison with the radiative effect of lower atmospheric CO 2 concentrations and the presence of ice sheets at the last glacial maximum (LGM) is investigated with the climate system model CLIMBER-2. Equilibrium experiments reveal that most of the global cooling at the LGM (?5.1°C) relative to present-day conditions is caused by the introduction of ice sheets into the model (?3.0°C, 59%), followed by the effect of lower atmospheric CO 2 levels at the LGM (?1.5°C, 29%). The biogeophysical effects of changes in vegetation cover are found to cool the LGM climate by 0.6°C (12%). They are most pronounced in the northern high latitudes, where the taiga-tundra feedback causes annually averaged temperature changes of up to ?2°C, while the radiative effect of lower atmospheric CO 2 in this region only produces a cooling of 1.5°C. Hence, in this region, the temperature changes caused by vegetation dynamics at the LGM exceed the cooling due to lower atmospheric CO 2 concentrations.