The impact on atmospheric climate of future land-use changes relative to the increase in greenhouse gas (GHG) concentrations is assessed in time-slice simulations with the ARPEGE-Climat atmospheric general circulation model (AGCM). Future land cover maps are provided by the IMAGE2.2 integrated model, developed by RIVM. We show that the relative impact of vegetation change to GHG concentration increase is of the order of 10% for a B2 scenario, and can reach 30% over localized tropical regions.