Formalised elicitation of expert judgements has been used to help tackle several problematic societal issues, including volcanic crises and pandemic threats. We present an expert elicitation exercise for Piton de la Fournaise volcano, La Réunion island, held remotely in April 2021. This involved 28 experts from nine countries who considered a hypothetical effusive eruption crisis involving a new vent opening in a high-risk area. The tele-elicitation presented several challenges, but is a promising and workable option for application to future volcanic crises. Our exercise considered an “uncommon” eruptive scenario with a vent outside the present caldera and within inhabited areas, and provided uncertainty ranges for several hazard-related questions for such a scenario (e.g. probability of eruption within a defined timeframe; elapsed time until lava flow reaches a critical location, and other hazard management issues). Our exercise indicated that such a scenario would probably present very different characteristics compared to recent eruptions, and that it is fundamental to include well-prepared expert elicitations in updated civil protection evacuation plans to improve disaster response procedures.

This Progress Report reviews the geographical literature concerning environmental hazards and risk focussing particularly on areas that require and enhance interdisciplinary working between human and physical geographers. Although there are still substantial gaps between disciplinary siloes, there is a growing recognition that critical interdisciplinary work is vital. Key areas include early warning, urban planning, hazard and risk mapping, scientific advisory processes, risk communication and institutional geographies. We review some of this work, examine emerging theory and consider the opportunities for greater knowledge exchange between disciplines using critical physical geography and cognate approaches.