Volcanic hazard exacerbated by future global warming-driven increase in heavy rainfall

Abstract

Heavy rainfall drives a range of eruptive and non-eruptive volcanic hazards. Over the Holocene, the incidence of many such hazards has increased due to rapid climate change. Here, we show that extreme heavy rainfall is projected to increase with continued global warming throughout the twenty-first century in most subaerial volcanic regions, increasing the potential for rainfall-induced volcanic hazards. This result is based on a comparative analysis of nine general circulation models, and is prevalent across a wide range of spatial scales, from countries and volcanic arcs down to individual volcanic systems. Our results suggest that if global warming continues unchecked, the incidence of primary and secondary rainfall-related volcanic activity—such as dome explosions or flank collapse—will increase at more than 700 volcanoes around the globe. Improved coupling between scientific observations—in particular, of local and regional precipitation—and policy decisions may go some way towards mitigating the increased risk throughout the next 80 years.

State-dependent impact of major volcanic eruptions observed in ice-core records of the last glacial period

“…This suggests a state-dependent climate response with more pronounced Greenland (Antarctic) cooling following eruptions during GS (GI), or a more complicated difference in the climate response that is encoded in different sensitivities of the δ 18 O proxy to the volcanic cooling. Alternatively, there could be a state-dependent volcanic forcing, potentially related to differences in atmospheric moisture and circulation, or a modulation of the volcanic activity by the climate state (Cooper et al, 2018;Swindles et al, 2018;Farquharson and Amelung, 2022). We indeed find slightly larger sulfur deposition estimates in Greenland (Antarctica) during GS (GI) (Fig.…”

The influence of water-saturation on the strength of volcanic rocks and the stability of lava domes

“…This link between geohazards and the high-rainfall tropical climate echoes a broader trend of rainfall-induced hazards observed at volcanoes elsewhere in the Caribbean, including dome collapses (Matthews et al, 2002;Matthews and Barclay, 2004;Carn et al, 2004) and seismicity (Matthews et al, 2009). In a comparative analysis of global climate models, Farquharson and Amelung (2022) showed that models consistently project an increase in heavy rainfall across the volcanic areas of the Caribbean over the next eight decades. In Figure 1c, we plot projected change in heavy rainfall over La Soufrière de Guadeloupe obtained from the MRI-CGCM3 general circulation model of Japan's Meteorological Research Institute: clearly, the propensity for heavy rainfall events is set to increase in the near future (see also Cantet et al, 2014), even under the most ambitious climate change mitigation strategies (i.e.…”

“…(RCP 8.6), an intermediate emissions scenario (RCP 4.5), and a "very stringent" pathway, whereby global carbon dioxide emissions decrease to zero within 80 years (RCP 2.6). Further details are given in Farquharson and Amelung (2022).…”

“…In tropical environments, increasingly frequent bouts of intense precipitation (not only during the so-called hurricane or rainy season but also at other times of the year in the Tropics) may directly trigger mass-wasting events (as observed elsewhere in the Caribbean: Matthews et al, 2002;Carn et al, 2004;Taron et al, 2007;Matthews et al, 2009 andin other settings: Yamasato et al, 1998;Elsworth et al, 2004), or facilitate other internal or external trigger mechanisms such as magma movement (Reid et al, 2010), pressurisation (Reid, 2004;Heap et al, 2021b), or basal spreading (van Wyk de Vries and Francis, 1997). For the majority of subaerial volcanoes, climate models project an increase in such meteorological events (Farquharson and Amelung, 2022). In the context of water-weakening and related hazards, climate change may also be important in terms of sea level rise.…”

“…As a result, volcano stability models should, where and when appropriate, use the mechanical properties for water-saturated volcanic rocks. Third, the frequency of landslides and the failure and collapse of volcanic slopes and domes increases following heavy rainfall (Kerle and van Wyk de Vries, 2001;Matthews et al, 2002;Matthews and Barclay, 2004;Simmons et al, 2004;Taron et al, 2007;Saucedo et al, 2008;Hicks et al, 2010;Vázquez et al, 2022), which will likely be exacerbated by the increase in heavy rainfall expected given the current trend in global warming (Farquharson and Amelung, 2022).…”