The PNNL Vulnerability Assessment Program explores approaches for assessing the significance of potential future changes in climate for natural resources and socio-economic systems. This report focuses on development of quantitative indices for vulnerability. Developing proxy variables and indicators for use in modeling or observation enables sophisticated vulnerability analyses that integrate environmental and social perspectives. A prototype system has been exercised for 39 countries, summarizing proxies for sensitivity and adaptation capacity in a vulnerability-resilience index. An extensive uncertainty analysis was performed.