Research over the last four years has considerably furthered understanding of LA-I. Further progress is expected over the next four years in understanding what the most appropriate formulation for land processes in climate and NWP models is, how these processes operate in the climate system, and how they can be specified by remote sensing data. These ideas will be synthesized with four-dimensional data assimilation systems for improved model initializations and generation of better land surface-atmosphere climatologies. Progress should also occur in understanding how land processes couple back to atmospheric processes, and the details of their atmospheric response. The focus provided by GEWEX programs over this period should help to considerably promote these advances.