Until recently, the main environmental concerns associated with information and communication technologies (ICTs) have been their use-phase electricity consumption and the chemicals associated with their manufacture, and the environmental effects of these technologies on other parts of the economy have largely been ignored. With the advent of mobile computing, communication, and sensing devices, these indirect effects have the potential to be much more important than the impacts from the use and manufacturing phases of this equipment. This article summarizes the trends that have propelled modern technological societies into the ultralow-power design space and explores the implications of these trends for the direct and indirect environmental impacts associated with these new technologies. It reviews the literature on environmental effects of information technology (also with an emphasis on low-power systems) and suggests areas for further research.