Viewed from space, the dramatic decline of the summer Arctic sea ice pack is probably the most obvious large scale change on the surface of our planet over the past decade. This drop in areal extent has significantly outpaced the predictions of most current climate models. Given the critical role that sea ice plays in the climate system as both an indicator and agent of change, understanding what may be missing and what must be treated more realistically in these models is essential to predicting the future trajectory of the polar sea-ice covers. The implications for global climate, the world ocean system, polar ecosystems, and for Native communities in the Arctic and for society as a whole, are far-reaching. As a material, sea ice is a composite of pure ice with brine and air inclusions on the sub-millimeter to centimeter scale, while the ice pack is structured on scales ranging from centimeters to hundreds of kilometers. Modeling the role of sea ice in the climate system involves mathematically characterizing nonlinear interactions of the ice with the ocean and atmosphere, and devising efficient methods of using information on smaller scales in parameterizing processes on larger scales. In this symposium, the panel explores the current state of large scale sea ice models and key processes from the micro-scale to the global-scale which must be understood better in order to improve the predictive capabilities of these models.