Geoengineering and the Middle Ages: Lessons from Medieval Volcanic Eruptions for the Anthropocene

Abstract

AbstractThe existential challenge of mitigating anthropogenic climate change encouraged serious discussions on geoengineering approaches. One of them, Solar Radiation Management (SRM), would mean inserting aerosols into the atmosphere, thus imitating and perpetuating the cooling effects of large volcanic events, such as the 1815 Tambora eruption. However, artificially inserting sulphur aerosols into the atmosphere is connected with considerable uncertainties. One of them, pointed out by several climate scientists, is the different effects on temperature and precipitation in different parts of the globe. These are not the only ones, though. As the largest volcanic eruptions have taken place during the medieval times (ca 500–1500 CE), historical research can reveal further uncertainties in dating these eruptions and their connected socio-environmental effects, and hence on the actual climate and social impacts we might expect from SRM. A combination of humanist and scientific research on past volcanic eruptions therefore has the potential to produce a more precise understanding of past volcanic eruptions and their climatic consequences. As long as we do not acquire a consistent multi-disciplinary perspective on past volcanic eruptions, extreme caution should be taken before investing in geoengineering measures that include the artificial injection of sulphur aerosols in the atmosphere.