Rapid changes in climate in the polar regions are causing observable ecological impacts of various types and degrees of severity at all ecosystem levels. Even larger changes and more significant impacts are anticipated. As species respond to changing environments over time, their interactions with the physical world and other organisms can also change, which can trigger cascades of impacts throughout entire ecosystems. Evaluating the interrelated components of polar ecosystems is essential to understanding their vulnerability and resilience to climate forcing. “Frontiers in Understanding Climate Change and Polar Ecosystems” summarizes a workshop held to address these issues.