This chapter considers the challenges surrounding the management of extreme volcanic risk. We examine eruption scenarios based on past episodes and assess the key issues that might arise should similar events occur in the future. The nature of such eruptions will entail transboundary and multi-scalar hazards. In a globalised world, the geopolitical and societal issues that are likely to emerge cannot all be predicted, and communication technologies themselves are likely to be affected. We explore two aspects: communication prior to the eruption, and communication during the eruption. To the best of our knowledge, all large eruptions are presaged by sensible phenomena but the enduring challenge for volcanic hazard assessment and risk management will remain the uncertainty surrounding evaluations of the likelihood, timing, nature and magnitude of potentially damaging activity. At present, too, communication of volcanic risk beyond the borders of the country where the volcano is located is generally patchy and unsystematic in most parts of the world (with the exception of the threat of ash clouds to aviation). In the preparatory phase, it is also critical to establish robust communication strategies that are resilient during an eruption. Such strategies would be essential for communicating the availability of supplies, the extent and nature of damage, and the ongoing status of the eruption.