In mid-January 2022, most people didn’t notice anything special, but geologists knew we dodged a bullet. The Hunga Tonga-Hunga Ha’apai volcano erupted in Tonga, sending enough water into the atmosphere to briefly warm the planet. The eruption was one of the largest ever recorded; it essentially blew up an island, created tsunamis, and caused damage equivalent to over 18% of Tonga’s GDP.

We were lucky the eruption lasted only 11 hours — had it lasted longer, the damage would have spread to other areas in southeast Asia, one of the most densely populated areas in the world, which also hosts vital shipping lanes and key global agriculture and infrastructure. If it had lasted longer and been a bit stronger, we could have had a global catastrophe.

A global catastrophe that, one volcanologist warns in a commentary in Nature, we are woefully unprepared for.

If there was a 1 in 6 chance of my house falling down, I’d do something about it

Researchers classify volcanic eruptions in something called the Volcanic Explosivity Index (VEI). This index classifies eruptions in terms of total volume of ejecta, cloud height, and types of eruption (some can be more gentle, some can be more explosive). The VEI ranges from 1 to 8, with 1 being a “chill” Hawaiian eruption, and 8 being an absolute catastrophe and possibly, a civilization-ender.

VEI 8 eruptions are relatively rare (the Yellowstone eruption from 2.1 million years ago and the Toba eruption from 74,000 years ago are good examples) — but VEI 7 eruptions are not that rare. In fact, the odds of such an eruption within this century is around 1 in 6, which is way too close for comfort.

The last such eruption was the 1815 eruption of Mount Tambora. This eruption, the largest ever recorded in human history, shrouded the planet in a blanket of aerosols that blocked a part of the solar rays, triggering the “year without a summer.” Crops failed worldwide. It was a global catastrophe.

So what if it happened again?

Michael Cassidy from the University of Birmingham and Lara Mani from Cambridge University warn in their Nature commentary that the risk of a major volcanic eruption within decades is significant.

A 1 in 6 chance is a roll of a dice. If you get the bad side, you get burned. The world is very different compared to 1815 — in many ways, because we’re so interconnected and interdependent, the eruption would hit us much worse, and the damage would be outright devastating.

It’s probably safe to say with the way the world is now, one bad year in which crops fail worldwide would trigger not just famine, but also riots and war. So we’d probably be wise to prepare. But how can we prepare?

Research, research, research

Just like with pandemics, the preparation starts with studies. The world has around 1,300 active volcanoes (volcanoes that have erupted in the past 10,000 years), but there are very likely other volcanoes whose recent eruptions have not been detected yet. Having a solid understanding of which volcanoes are active and where is a useful first step.

This is particularly important because there’s a good chance many large volcanoes are unknown to us. Out of the 97 large-scale magnitude volcanic eruptions detected so far, only a few can be attributed to specific volcanoes — the site of many others is a mystery. In fact, researchers believe that 80% of VEI 6 eruptions before year 1 AD are not known.

From there on, we’d probably we bise to monitor the volcanoes. Thankfully, a lot of recent advancements are enabling a better monitoring. Geologists typically look for small earthquakes that often preface eruptions, gas release, and ground deformation — all of which could indicate potential upcoming eruptions. However, we’re not doing a good enough job even with the volcanoes we know — just 27% of the eruptions since 1950 have been monitored with at least one instrument, letFrom here on, we’d probably be wise to monitor our volcanoes. Thankfully, a lot of recent advancements are enabling better monitoring. Geologists typically look for small earthquakes that often preface eruptions, gas release, and ground deformation — all of which could indicate potential upcoming eruptions. However, we’re not doing a good enough job even with the volcanoes we know — just 27% of the eruptions since 1950 have been monitored with at least one instrument, let alone volcanoes we don’t know about yet. Satellite data is increasingly becoming useful for volcano monitoring, but the technology is not quite there yet, and volcano-dedicated satellites are still absent. alone volcanoes we don’t know about yet. Satellite data is increasingly becoming useful for volcano monitoring, but the technology is not quite there yet, and there volcano-dedicated satellites are still missing.

“Where local ground-based monitoring is not feasible, particularly in remote areas, satellite and aerial observation become essential. In addition to monitoring thermal, gas and deformation changes, satellites could provide real-time mass eruption rates, plume heights and imagery for disaster relief. But current satellites lack the necessary resolution in time and space,” the researchers write.

“For more than two decades, volcanologists have called for a dedicated volcano-observing satellite to be launched. Much progress has been achieved by sharing satellites, yet a step-change in volcano surveillance could be achieved with a dedicated satellite observing in the infrared, or high-altitude drones that act as pseudo-satellites for months at a time,” they add.

Another important preparation would be further research into historical and geological records, looking at areas where the risks of an eruption are highest (often in under-studied areas such as southeast Asia), and analyzing potential risks and adaptation and mitigation strategies. From thereon, ramping up preparedness in terms of humanitarian response, and launching education programs, would both be worthwhile initiatives.

Volcano engineering is not on the table at this point. If a major volcano were to erupt, we’d have to adapt and react — but we have the means to do better than we are now.

Unlike pandemics, we can’t invest in the prevention of volcanic eruptions. But we can pay more attention and be prepared to react accordingly.

“Will humanity learn from volcanology’s near miss in Tonga, or will a large-magnitude eruption be the next planet-disrupting event to catch the world unawares after the pandemic? Discussions must start now,” the researchers conclude.