Castells's influential work on the Information Age has hardly impacted on the environmental social sciences; and where it has, it has been mainly in terms of intrusions of global flows and networks in fragile environments. This paper explores to what extent and how environmental governance is changing under the conditions of the Information Age. On the waves of information and communication technologies and globalisation processes, a new informational mode of environmental governance-or informational governance¿is emerging, in which environmental information gains transformative powers. Information generation, processing, transmission, and use become fundamental (re)sources of power and transformation in environmental reform. As illustrated by several examples, the conventional powers of (state) authority in environmental protection are partly replaced by informational resources, flows, and processes in new governance arrangements and networks. These new modes of informational governance not only point at innovative means of environmental reform, but also pose a series of more critical questions related to new power constellations, (information) access and democracy, and structural uncertainties following multiple knowledges. Hence, a new research agenda emerges for the environmental social sciences.