Northern Eurasia is undergoing significant changes associated with warming climate and with socio-economic changes during the entire 20th century. Climatic changes over this vast landmass interact and affect the rate of global change through atmosphere-terrestrial-cryosphere feedbacks and through strong biogeophysical and biogeochemical couplings. Current and future interactions and feedbacks to the global system of this carbon-rich, cold region component of the Earth system remain to a large extent unknown. There are still large uncertainties in model representation of both precipitation and underlying processes that drive the carbon, hydrology and energy cycles of the northern high latitudes. Model representation of snow, snow redistribution, permafrost, effects of lakes and wetlands are marginal, a problem that is compounded by large uncertainties in observations. Many of the global modeling groups are developing Earth system model components that represent processes specific to the high-latitudes, including organic soils, permafrost, wetlands, ice sheet dynamics and/or biogeography; however, there is no robust or rigorous methodology for testing and evaluating model implementation. We invite presentations on this topic, as well as presentations linking observations at the surface, remote sensing and modeling, essential for model validation. Presentation of IPY results related to Northern Eurasia and its coastal zone are especially welcome. The Northern Eurasia Earth Science Partnership Initiative (NEESPI) is an interdisciplinary program of internationally-supported Earth systems and science research that addresses large-scale and long-term manifestations of climate and environmental change focusing on Northern Eurasia (http://neespi.org). The major NEESPI science question is: How do Northern Eurasia's terrestrial ecosystems dynamics interact with and alter the biosphere, atmosphere, and hydrosphere of the Earth? We invite papers on all areas of NEESPI science, including biogeochemical cycles in Northern Eurasia, the surface energy budget and water cycle in Northern Eurasia, climate and terrestrial ecosystems interactions in Northern Eurasia (land cover and land use, atmospheric aerosols, soil, and, in particular, permafrost changes that affect and are being affected by climate and ecosystems changes), "human dimension" that includes, in addition to regional impact studies of environmental changes, the feedback studies of societal and land use changes on regional and global environment and climate, and tools to address the Northern Eurasia studies (paleoclimatic reconstructions, present and past field campaigns, remote sensing, and modeling).