Explosive volcanic eruptions inject large volumes of ash and gas into the atmosphere, with significant environmental and climatic consequences. As human populations increasingly occupy volcanic regions, and as global trade, transport, and food systems become more interconnected, the impacts of eruptions are no longer confined to the host country. Even geologically “modest” events (e.g., Eyjafjallajökull 2010 CE) can trigger cascading, global-scale disruptions with serious economic, societal, and environmental repercussions. Studying large explosive eruptions in the geological record can help to prepare for volcanic-induced disruptions in the future because it provides a critical opportunity to (1) assess their short- (<1 year) and long-term (>1000 years) impacts on the Earth system, (2) improve calibration of climate model simulations, (3) constrain the frequency of large or environmentally significant eruptions, and (4) evaluate how human activity may be pushing Earth system responses to volcanism into new states. However, despite substantial recent advances, major challenges remain in quantifying eruption impacts across different magnitudes, styles, and regions. This special issue contains contributions that address these challenges by improving reconstructions of past eruptions, elucidating climate system responses, and assessing implications for human infrastructure and society. It also includes studies that inform policy development and volcanic risk management, particularly in regions vulnerable to disruptions of food, energy, and water resources. The special issue provides a hub for scientific research looking to advance interdisciplinary understanding of links between volcanism, climate, and society and enhance global preparedness for future volcanic crises.