Energy & Commodities risk-off · Tail risk
A what‑if from the future

What if a massive volcanic eruption grounds global aviation?

A VEI-6 ash-cloud (Pinatubo-class) grounds aviation and cools a crop season: long wheat/corn on yield loss, short jet fuel/airlines on grounded fleets, modest broad risk-off. The 1991 Pinatubo eruption is the direct analogue — ~0.5C of global cooling and measurable crop pressure the following year; the 2010 Eyjafjallajökull closure is the aviation-grounding template. The semiconductor 'water-stress' leg is again a climate_supply artifact and should be ignored — the root is right for grains, the fab channel is noise.

6%
our model probability
over Tail risk
prediction markets — the market's odds
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Anchored to measured history 6% · 90% range 0–13% · 17 dated precedents behind it — a wider range means thinner evidence

Every number ships with its receipt — the odds, the range, the precedents, and a public grade at Reality Check. The statistical machinery that produces it is proprietary.

The butterfly cascade

How this trigger trickles across markets, left → right — the root shock, its first‑order moves, then the ripple effects. Drag any node; tap a market for its real price history.

Resolution timeline — how this probability is moving

Our model's odds (electric blue) over time vs the market's (Polymarket, amber), from the past toward the Tail risk horizon. Each dot is a real macro event that nudged the probability — green pushed it up, red pushed it down. Tap a dot for the source. Loading the probability audit trail…

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What it would mean

If this plays out, it is a risk-off shock. A large explosive eruption injects ash into the stratosphere, grounding global aviation and cooling crop yields for a season. The trigger decomposes into signed root‑shocks — Climate/crop supply ▲ · Risk appetite ▼ — which propagate through our causal graph to the markets below.

Methodology. Probability and impact are anchored to history and scored against what actually happens — wins and losses, in public, at Reality Check. Market odds live from Polymarket & Kalshi. By Vikas Singh, Quantitative Strategist. Updated 2026-08-13.