Research Priorities on Vulnerability, Impacts and Adaptation: Responding to the Climate ange Challenge consists of 33 topics presented in three sections: Information to Support Policymaker Decisions, Systems and Regions and Emerging Topics. Each of the 33 topics includes a description of why the research is needed, followed by several paragraphs describing specific activities that respond to that need. A short bulleted list thereafter highlights representative examples of critical activities from the broader set of proposed activities for each Research Topic.