Climate geoengineering is increasingly suggested as a mitigating option for the ongoing anthropogenic warming. Two approaches, greenhouse gas removal and solar radiation management, are the most commonly suggested options. The latter seeks techniques to reduce incoming solar radiation on the Earth’s surface to cool down the planet. Past volcanic eruptions are commonly used as an analogue to learn more about this approach. Large volcanic eruptions can inject sulphur compounds far into the stratosphere, where these are oxidized and start travelling towards the poles. The aerosols absorb and scatter light in the stratosphere and therefore less solar radiation reaches the ground, which cools the Earth's surface. By studying past volcanic eruptions, scientists have underlined the significant uncertainties related the climatic impacts associated with plans to cool down the global climate with the solar radiation management technique.Geoengineering actions, like artificially reducing the incoming solar radiation, may have also disastrous human consequences. However, these risks have not been addressed in scientific or public discussions. Nevertheless, history has demonstrated how volcanic-related climatic shocks can paralyze sensitive food systems and cause considerable social distress.This talk will address the possible climatic, agricultural and socio-economic consequences of reduced solar radiation, by exploring the relationship between 17th century tropical volcanic eruptions and Finnish peasant society. The talk demonstrates how volcanic-related climatic cooling is associated with sharp agricultural decline in the early modern Finland. Moreover, sudden impoverishment, and in some cases even famine, followed these agricultural crises. However, it is also discussed how the strengthening of the Swedish Realm over the 17th century reduced the economic impacts, which became then more pronounced among the disadvantaged segments of the society. The talk will provide evidence that climatic changes caused by reduced solar radiation can cause distress on many.
Dr. Heli Huhtamaa received her doctoral degree in History form the University of Eastern Finland, Joensuu, in 2017 and a PhD of Science in Climate Sciences from the University of Bern, Switzerland, in the same year. Her research explores with interdisciplinary approaches the human consequences of the past climate variability, focusing mostly on early modern northernmost Europe. In addition to Bern and Joensuu, she has worked as a researcher at the Universities of Utrecht and Turku. Currently, she is a SNF Research Fellow at the Heidelberg Centre for the Environment, Heidelberg University, carrying a research project entitled "Climate extremes and population dynamics in the northern Baltic Sea region prior to the industrialization (1636–1935).