Impact of the Tambora Volcanic Eruption of 1815 on Islands and Relevance to Future Sunlight-Blocking Catastrophes

Abstract

Abstract Island nations may have potential long-term survival value for humanity in global catastrophes such as sun-blocking catastrophes from nuclear winter and large magnitude volcanic eruptions. One way to explore this issue further is to understand the impact on islands after the largest historically observed volcanic eruption: that of Mt Tambora in 1815. For each of the 31 large populated islands selected, we conducted literature searches for relevant historical and palaeoclimate studies. We also analysed results from a reconstruction (EKF400v2), which uses atmospheric-only general circulation model simulations with assimilated observational and proxy data. From the literature review, in those islands with data, there was evidence for weather/climate anomalies in 1815-1817 for all of them (100%; 29/29), impaired food production in 67% (8/12), and food insecurity/famine in 33% (4/12). Based on the EKF400v2 reconstruction for temperature anomalies (compared to the relatively “non-volcanic” reference period of 1779 to 1808), all but four islands showed statistically anomalous temperature reductions in the 1816-1817 period (for most p<0.00001). In the peak impact year of 1816, the lowest anomalies were seen for islands in the Southern Hemisphere (p<0.0001), the Indian Ocean (p<0.0001), and in the tropics and subtropics of the Southern Hemisphere (p=0.0057). In conclusion, the findings of both the literature review and reconstruction simulations suggest climatic impacts of the Tambora eruption for nearly all these 31 large islands. But islands in the Southern Hemisphere, in particular the Indian Ocean and the tropics and subtropics of the Southern Hemisphere, experienced relatively smaller temperature anomalies.