This project will investigate, through three case studies, the relationship between technologies and practices of environmental sensing and citizen engagement. Wireless sensors, which are an increasing part of digital communication infrastructures, are commonly deployed for environmental monitoring within scientific study. Practices of monitoring and sensing environments have migrated to a number of everyday participatory applications, where users of smart phones and networked devices are able to engage with similar modes of environmental observation and data collection. Such “citizen sensing” projects intend to democratize the collection and use of environmental sensor data in order to facilitate expanded citizen engagement in environmental issues. But how effective are these practices of citizen sensing in not just providing “crowd-sourced” data sets, but also in giving rise to new modes of environmental awareness and practice? Through intensive fieldwork, study and use of sensing applications, the case studies will set out to contextualize, question and expand upon the understandings and possibilities of democratized environmental action through citizen sensing practices. The first case study, “Wild Sensing,” will focus on the use of sensors to map and track flora and fauna activity and habitats. The second case study, “Pollution Sensing,” will concentrate on the increasing use of sensors to detect environmental disturbance, including air and water pollution. The third case study will investigate “Urban Sensing,” and will focus on urban sustainability or “smart city” projects that implement sensor technologies to realize more efficient or environmentally sound urban processes.