GREENCYCLESII

T5.3 Matteo Willeit

The main objective of the work is to improve understanding of the processes involved in the climate-vegetation interaction to assess the importance of biogeophysical and biogeochemical feedbacks in the Climate System. In particular the project will focus on the influence of model parameterizations and process representation on the strength of these feedbacks. The need for this research is given by the large differences in the strength of climate-vegetation coupling as currently modeled by climate models of various complexity. The work will be performed using the CLIMBER family of Earth system models of intermediate complexity. In a first stage CLIMBER-2 will be used to run large ensembles of simulations to test the sensitivity of the model to different parameterizations/representations of surface processes that have an important role in determining the strength of biogeophysical feedbacks.
In a second stage the new CLIMBER-4 version currently under development at PIK will be used to model the role of climate-vegetation feedbacks for future climate change projections. CLIMBER-4 will incorporate the LPJmL (Lund-Potsdam-Jena managed Land) dynamic global vegetation model and will thus allow to simulate the impact of land use changes on future climate under various scenarios on decadal-centennial time scales. The incorporation of the land surface scheme and LPJmL into the new CLIMBER-4 will be part of this project.