Is it Ethical to Use a Single Probability Density Function?

RAND working papers are intended to share researchers' latest findings and to solicit informal peer review. They have been approved for circulation by the RAND Justice, Infrastructure and Environment Division but have not been formally edited or peer reviewed. Unless otherwise indicated, working papers can be quoted and cited without permission of the author, provided the source is clearly referred to as a working paper. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors. RAND ® is a registered trademark. Abstract Addressing climate change requires both quantitative analysis and ethical reasoning. But the character of many climate-related decisions – in particular deep uncertainty, competing values, and complex relationships among actions and consequences – can make it difficult to use the most common types of quantitative analysis to support appropriate ethical reasoning. This essay will describe Robust Decision Making (RDM), one of a new class of methods for quantitative analysis that can help resolve some of these difficulties, and situate RDM in the framework for ethical reasoning and deliberation laid out in Amartya Sen's Idea of Justice. Two example applications will illustrate these ideas: one examining how greenhouse gas mitigation policies might appropriately address the threat of abrupt climate change and the other addressing management of the Colorado River in the face of climate change and other changing conditions.