The quality of the natural environment has become one of the primary concerns in present society. However, very little has been done to illuminate the various connections between our household purchases and the effect they can have on the quality of our health and environment. Decision support tools are becoming more important as more people are required to incorporate much more diverse information into their everyday decisions regarding health and environmental impacts. Many of these people will be less than expert computer users with little tolerance for difficult interfaces. The question arises - how do system designers construct a satisfying, interactive interface that best suits this diverse user community? This book describes work towards this goal by describing two usability evaluations conducted that were designed to assess previous environmental decision support tools with concepts for new designs. This book is addressed towards usability professionals interested in reviewing the principles of user-centered design and researchers in sustainability interested in understanding how decision support tools can be used to transmit knowledge and increase public awareness.