Volcanism and Climate Change

Induced cooling of Pinatubo

~0.5C cooling (McCormick et al., 1995)

Size of Pinatubo ash cloud and exacerbation

~1000km across, exacerbated by nearby typhoon system (McCormick, 1995)

Why does dust stay in the atmosphere longer

Because it does not interact with precipitation above the tropopause (Oppenheimer, 2025)

Self-limiting effect of sulfur

when too much sulphur is released the aerosol particulates become to large and fallout (Marshall et al., 2025)

Interactions with climate systems

Large eruptions may induce El Nino (Oppenheimer, 2025)

Importance of water vapour

Water vapour release can cause localised warming particularly with submarine eruptions (Tonga, 2022) though this is more regionalised and short-term compared to sulphur aerosol (Marshall et al., 2025)

Paper describing failures of ice core collection

(Marshall et al., 2025) states this and writes that SAOD is a better indicator of impact (and therefore possibly dendochronology).

Importance of latitude

however minute latitude difference is tends the aerosol towards one hemisphere; an eruption at a high latitude will have extremely strong hemispheric effet (e.g. Laki) (Marshall et al., 2025)

Avg. wait time between VSSI >6Tg eruptions

50/45yrs, a gap in these cycles coincided with the height of the Roman Empire (400s CE), lack of wait times may have also caused LIA (Buntgen et al., 2026)

Paper showing societal impact of volcanic eruptions

(Buntgen et al., 2026) indlucing food security, civil unrest, demography and culture/identity

Cooling effect of sulphur dioxide globally

-0.5C forcing (IPCC, 2021)

Paper showing uncertainty of modelling

(Timmreck, 2012) shows that 10,000yrs of volcanic eruption recordings similar to the last milennia would be needed to further narrow down the estimates of forcing.

Chlorine activation

ozone depletion may be heightened because of increased nucleation points from sulfate aerosol (Timmreck, 2012)

Unusual winter effects of tropical eruptions

Warm winters over NH continents and cold winters over Greenland / Middle East; due to a heightened polar vortex due to abnormally high equatorial temperatures (pressure gradient) (Timmreck, 2012)

Impact on precipitation

Globally reduced, possibly due to increased nucleation and transport into the troposphere? (Timmreck, 2012)

Stats of Younger Toba eruption (74kya)

Cooling may have reached -12C and perhaps more in equitorial continents (e.g. Africa); possible civilisation bottlenecking effect (Timmreck, 2012)