The eruption of Mount Pinatubo on June 15, 1991 in the Philippines was the second largest volcanic eruption of the 20th century.

The result of the volcano eruption was destruction. The eruption caused mass flooding in the surrounding areas, coated whole communities in a thick layer of ash, and took out telecommunications for weeks. According to a new commentary article, we got lucky in that eruption. If the eruption had gone on longer, it could have been a lot worse. They say that a similar disaster could have dire global consequences and that we need to be more prepared.

Many more people could have been killed if the volcano had been in a more populated area. The eruption could have caused mass infrastructure and supply chain disruptions. Climate destabilization could have easily been caused by a larger event. The year without a summer was caused by the eruption of Mount Tambora in 1816. Crops failed around the world.

There is a one in six chance of an eruption 10 to 100 times larger happening in the next century according to Cassidy and Mani. A roll of the dice is one in six. The world is not prepared for such an event. It should be a wake-up call.

How much should we be worried? How can we prepare for the big event? Cassidy told me about it. It was lightly edited for clarity and length.

Lauren Leffer wonders why this commentary is being published now.

I believe it came from covid. We were all locked down, but we were all aware that it could have been worse. Since now people have looked into it, I think it's a good bet that there will be a pandemic this century. Lots of countries weren't prepared for it Vaccines and other treatments were produced by the Biomedical community. I wondered how my field, volcanology, would cope with something like that. My first thought was probably not very well.

I think it's down to the size of the community and the amount of investment. Laura works for the Centre for the Study of Existential Risk. She was also thinking about this.

This photo taken on January 16, 2022 shows destroyed beach resorts in the Hihifo district of Tonga’s main island Tongatapu following the January 15 eruption of the nearby Hunga Tonga-Hunga Ha’apai underwater volcano.

Gizmodo asked what gives volcanic eruptions such potential for chaos.

There are large eruptions that can cross borders. There are a lot of different dangers. Ash flow over thousands of kilometers can interrupt things like electricity and potentially collapse roofs of important buildings, buildings that could be critical to our sewage or other infrastructure. There are things that can come off of volcanic flows. We've seen the destruction caused by the Krakatoa tsunami, as well as volcanic flows. There is a fatality rate of nine in 10 for pyroclastic flows. There are things that can happen due to rain and loose, unconsolidated ash that can cause devastating floods.

The more immediate impacts are what they are. You didn't pay much attention to the long term climate issues.

Cassidy said yes.

How prepared are you for the possibility of disruptive eruptions?

Cassidy thinks it depends on location. Even with the resources it has, the US, Japan, and Indonesia are very good at this because they have a lot of resources set up to monitor volcanoes. Lots of successful operations have taken place in the Caribbean. There are some eruptions that we don't know about. That can be problematic. One point is location.

We were more resistant to smaller eruptions than we were in the past, which is great. Innovations with health care and monitoring are to blame. I don't think this includes the bigger eruptions that are more unprecedented. This is the largest eruption since 1816 in Tambora. We are less prepared for those larger events.

You start with the example of the recent Tonga eruption in the commentary article, and describe all the ways we got lucky with it: The duration was relatively short, and it wasn't in a densely populated area. What would the worst case scenario have looked like?

Cassidy thinks it was a magnitude 5 or a magnitude 6 eruption. About 10 times or 100 times less powerful than what we are talking about. It could have been hazardous if that eruption happened in an area with a lot of critical infrastructure. This is where we aren't as prepared.

It is possible to tell if an eruption is going to happen. We are terrible at telling what style it will be. It could be either a lava flow or an explosion. How large will it be? We don't know how to predict or forecast that

If that volcano event happened in high density areas such as southeast Asia or the coast of the Philippines, it could cause huge problems for global trade.

You mention the magnitude of an eruption. People are familiar with hurricanes and earthquakes, but how are eruptions graded?

They are graded on the amount of rock or ash they can emit. The Tambora eruption is the equivalent of covering the UK in 40 centimeters of ash.

It would take about 10 centimeters of ash to cover the entire U.S. These are big eruptions. A magnitude 8 eruption is not very common. There is a chance of one in 170.

Can you walk me through how you got to that figure, which is six figures for a magnitude 7 eruption or greater? It is based on a scientific study.

They can look at ice core. They can pick out big eruptions from the amount of sulfur that they emit. If you see a sulfur peak in the ice core, that can be a sign of a large eruption. There were 97 of them through a 60,000-year period. The eruptions were the size of Tambora and above.

When they did this in 2021, they discovered that eruptions of magnitude 7 or higher occur every 625 years, which is about one in seven. This is not a big data set because there were only three or four of those that they found. That is about one every 150 years. The geological record has a lot of information. There is a repeat rate of super options at about 17,000 years. It's similar. I combined the risks of one in 150 and one in seven to give us one in six.

Do you feel like the world would be thrown into chaos by a volcanic eruption?

Although it is a high risk, Cassidy thinks no is the answer. We won't have an eruption of that size in the next 100 years. If there was a chance that my house would fall down in my lifetime, I would do something about it. I think I'd take out an insurance policy on it. I would invest money to try and improve that and make my family safer. It is odd to me that we are not doing that for volcanos.

To get into what we could be doing differently. You compare asteroids to planetary defense systems that are in development. I can imagine what it would be like to throw an asteroid off course. How do you prevent a volcano from eruption?

Cassidy doesn't think we can at the moment. It is in the area of science fiction. It is a mistake to suggest that we stop at that location.

There is an argument that we could look into this and begin researching it. There are some obvious and worrying risks. Any kind of research needs to be done with care. We might be in a position to mitigate eruptions in the future if we start researching these methods now.

There are things we can do that would be helpful and help mitigate the risk. We don't know where some of the big spikes in the ice core came from, so we need to figure out where the volcanoes are. We need to locate those. I think we will be doing a lot of good if we find those.

Communities can be prepared around those volcanoes. Things like nowcasting can be developed as well. We may be able to send information to people's devices to suggest what they can do. If there is a chance of more than five centimeters in their location, tell them to remove ash from their roof.

The house fell down as a metaphor.

Cassidy said that the roof collapsing was true. Good point.

What do you think about our current monitoring? There are big holes. What is the total length of it?

I think countries do an amazing job with the resources they have. In Indonesia, the Caribbean, and Mexico, I have witnessed this firsthand.

There is a problem that they are run from. It means that countries that invest in volcanic research like the U.S., for example, are better prepared. They are better prepared for volcanic eruptions than less developed countries such as Indonesia and the Philippines. Some areas aren't very well monitored. Half of the volcanoes in Indonesia are monitored correctly.

How often do we know that a volcano eruption is imminent? When we monitor it, how much warning do we get?

We are pretty good at telling if an eruption is imminent. That is where it becomes more difficult in terms of what style of eruption will occur. Predicting the size of eruption is difficult.

Gizmodo asked if we need more research to figure out the details. We need to always be prepared for the worst case for every volcano we monitor.

Cassidy thinks that we need more research and that things will get better. We don't know when a volcano will erupt or what style it will erupt in. It is similar to going to a doctor and trying to figure out when you will sneeze. It is possible that we will never get to that stage of precision. We need to set up our communities so that they are ready for a worst-case scenario. Our critical systems, like electricity and trade networks, are set up so that we can be more resistant to shocks like this.

There are a few places that are well prepared. In the article, you mentioned St.Vincent's Volcano Ready Communities project. What do you think a well-prepared place would look like?

It can mean a lot of community engagement, involvement, and education of both children and adults, so they can know what to do in case of a disaster. There were programs for several years in St.Vincent.

There are two levels of research, the local community level and the monitoring level. The big global picture is also included. These eruptions don't have borders, and they can have huge global effects. How do we get ready for that side of things?

Cassidy thinks we need more involvement from the UN or global bodies. Currently, every volcano observatory is run separately, and we need to have a global, coordinated community. There are policies that need to be in place in the event of a catastrophic eruption. Let's stop countries from banning exports. If there is a food crisis because of a global volcanic winter, then that will help alleviate it.

Monitoring networks can tell us when eruptions will happen. In the weeks or months prior to that, we can come up with plans to change trade if we know it is from a volcano that is capable of a large eruption. Extra water, masks, excess food, and backup electricity are available in that country. Proper investment and global coordination is what I believe we need.

A lot of this sounds similar to what we'd need for a major disaster. Yes, right?

Cassidy: Absolutely. There are many parallels to nuclear winters, asteroid winters, and other types of catastrophic risks. There are things that can be learned from previous eruptions.

We could potentially mitigate volcanic eruptions with more speculative, or sci-fi, ways. Is it possible to create a planetary defense system for volcanoes?

Cassidy says there are a few things. The after-effects of the atmosphere. One of the biggest risks for volcanic eruptions is the volcanic winter effect, where large amounts of sulfur are ejected into the stratosphere, and they spread across the world, and they cool the Earth. It can push around monsoon areas and wreak havoc on crops, so it's important to be aware of that. There were historic famines after some of these large eruptions. We know that it is a huge deal. Trying to counteract that is one of the most intuitive things. That could mean that the removal of sulfur aerosols in the sky could be sped up.

Big eruptions can have an effect on the atmosphere for up to five years. Short-lived global warming agents can be injected to counteract the cooling effect. That happened before the eruption took place.

The other way is being looked at, though I don't think it will happen in the near future. It is to begin drilling into the ground. We have drilled into pockets of magma at least three times. It shows us that we can interact with the bodies. These are small, nothing compared to what we are seeing. We might be able to increase the fracture networks around those magma bodies so they de-gas.

Is a pressure valve something you would like?

Cassidy is absolutely correct. It is just beginning to be looked at. They decided to make an international magma observatory after accidentally drilling into this magma pocket in one of the areas in Iceland. This could help us with more than one thing. It could make monitoring better. There could be sensors there. We may be able to learn how to manipulate eruptions.

Some of the consequences of volcanic eruption can be worsened by climate change. Can you tell me more about that?

Cassidy says it is nearly three effects. It stretches your humanitarian organizations and the countries that try and manage these sorts of disasters if you have more than one extreme weather event. It makes us more vulnerable to disasters.

The second reason is that, as you start to melt glaciers, as you start to increase sea level rise, as you start to increase rainfall, these can all have subtle but real effects on volcanic systems that have to do with stress inside the crust. We saw an increase in volcanic eruptions when we de-glaciated about 10,000 years ago. There is a chance that we will see more volcanic eruptions. We don't know if it's the next 100 years or the next thousands of years.

We might see increased atmospheric circulation if we enter a very hot climate. There are differences in the way our oceans are stacked. Any kind of eruption from the tropics might have a bigger effect.

The article mentions a dedicated satellite monitoring system. How would a system like that affect our ability to monitor?

Cassidy thinks this could look like a satellite. Once we have indications that an eruption is imminent, it could look like a pseudo satellite.

It wouldn't be able to replace current monitoring systems, but it would give us more tools. Predicting before. It can tell us how fast a cloud is spreading, which is something we didn't have in Tonga. We can get better information faster if we know how big an eruption is.