Climate responses to historical land cover changes

Abstract

This study assessed the biogeophysical effects of land cover change on climate using MPM-2 during the past millennium. Simulations based on the Climate and Environmental Retrieval and Archive (CERA) land cover dataset were carried out to equilibrium from AD 800 to 2000 after a spin-up time of 5300 yr. We concluded that there was a cooling biogeophysical effect of about 0.13°C in global mean annual temperature in response to historical deforestation, with a maximum cooling of 0.5°C over Eurasia and a minimum cooling of 0.02°C at low latitudes over the Southern Hemisphere. Much larger contrasts were found on a seasonal scale, while these changes were largely offset on an annual scale. Seasonally, cooling occurred in the middle northern latitudes and warming occurred in the low southern latitudes due to historical deforestation. The effect of land cover change was most pronounced over Eurasia, with a maximum cooling of approximately 0.8°C at middle latitudes during summer and a maximum warming of 0.1°C at low latitudes over the Southern Hemisphere during the Northern Hemisphere summer, owing to the changes in albedo and precipitation. These results suggest that changes in land cover triggered a chain of feedbacks in the climate system, and they highlight the need for further research in this area. © Inter-Research 2013.