Modelling climate response to historical land cover change

In older to estimate the effect of historical land cover change (deforestat ion) on climate, we perform a set of experiments with a climate system mode l of intermediate complexity - CLIMBER-2. We Focus on the biophysical effec t of the land cover change on climate and do not explicitly account for the biogeochemical effect. A dynamic scenario of deforestation during the last millennium is formulated based on the rates of land conversion to agricult ure. The deforestation scenario causes a global cooling of 0.35 degrees C w ith a more notable cooling of the northern hemisphere (0.5 degrees C). The cooling is most pronounced in the northern middle and high latitudes, espec ially during the spring season. To compare the effect of deforestation on c limate with other forcings, climate responses to the changing atmospheric C O2 concentration and solar irradiance are also analysed. When all three Fac tors are taken into account, dynamics of northern hemisphere temperature du ring the last 300 years within the model are generally in agreement with th e observed (reconstructed) temperature trend. We conclude that the impact o f historical land cover changes on climate is comparable with the impact of the other climate forcings and that land cover forcing is important for re producing historical climate change.