The goal of the project is to investigate the relationship between changes in lake and wetland extent and the regional carbon balance in northern Eurasia over the last half-century, and to predict the likely impacts of changes in lake and wetland extent on the carbon balance in this region over the next century. Our approach is to develop a historical time series of observed lake and wetland extent via a combination of high resolution, slow-repeat-cycle SAR data (primarily from ALOS/PALSAR) and low-resolution, fast-repeat-cycle passive microwave data (primarily from AMSR-E).