Professor Nick Pidgeon gives a talk for the Uncertainty, Risk and Decision Making seminar series. Events of the past 3 years - from volcanic ash, to climate change e-mails, to Fukushima - have brought home the importance of both handling and communicating environmental risks for both the public and for policy purposes. This talk will ask what we know about types of environmental uncertainty, and their significance and impacts for both policy decisions and communication with the public. I argue that despite longstanding evidence and research findings from the environmental social sciences there is little appreciable progress in the UK as elsewhere on the necessary strategic approach to supporting policy decisions and communicating uncertainty. Such an approach would combine 'strategic listening' with 'strategic organisation'. The forms of boundary organisation that might be needed to take up these tasks are also discussed.