Land-atmosphere interactions

There is substantial evidence that land use change and vegetation/soil/snow dynamics processes have a significant influence on climate on regional and global scales. The effect of these influences on the global scale has been found to be comparable in magnitude to the radiative effect of carbon dioxide. On the regional scale, these influences appear to be more important, and act on time scales of months and less. The paper presents evidence of the importance of landscape processes, including land use change, on climate. Results are shown on a regional scale comparing the relative importance of the radiative and biological effects of a doubling of CO:, and of landuse change from the natural to current landscapes. On the global change scale, results are presented comparing the sensitivity of the Earth's climate to anthropogenic increases of CO2, and from human-caused landuse change. The modelling tools used in these studies include the Regional Atmospheric Modeling System (RAMS) and the National Center for Atmospheric Research (NCAR) CCM, global model. Global data sets including the National Center for Environmental Prediction (NCEP) Reanalysis and regional data from the National Climate Data Center's (NCDC) historical data are presented to in order to provide confirmation of the modeling results.