In the past two decades Borneo has experienced heavy deforestation. Using 250m MODIS data we analyzed the deforestation patterns between 2002 and 2008. The research revealed that the major drivers of deforestation are linked to human activities. However, medium-resolution data cannot provide reliable information about forest degradation processes. For that sake we analyzed high resolution data covering two logging concessions in Sabah, applying conventional and reduced impact logging. The objective of the research was to analyze to what extent satellite remote sensing can estimate forest degradation and biomass loss caused by the different logging techniques. As both optical and radar data show severe restrictions in estimating carbon stocks of tropical forests, we applied a combined approach of active and passive sensors. This research provides crucial information, essential to improve the forest-certification system, an important process in REDD. If no measures are taken, the lowland forests of Borneo are expected to vanish within the next decade.