How do volcanoes impact the environment?

When a volcano erupts, there’s a plume of gas and a stream of magma. Now whilst magma can leave a trail of destruction, the volcanic gases also have a huge impact on the environment. This is something of interest to volcanologist Evgenia Ilkinskaya, who spoke with Izzie Clarke...

Evgenia - My favourite story is probably a relatively small eruption that happened in 2010 in Iceland. This little eruption was in the middle of nowhere up on the mountain. And at this point in time it was still very much winter in Iceland so it was very snowy and we reached the eruption site at about the time when the sun was coming up. So you had this virgin white snow and huge red lava fountains coming out straight from that snow and black ash deposits put down around the volcano.

So it was just that combination of colours: white and red and black, and it was just an absolutely fantastic scene. And it was making these sounds like an old school steam engine, a train coming past. I’m not particularly religious myself, but that scene was something you really felt in the presence of something bigger and much more amazing than anything humans could ever make.

Izzie - Evgenia’s research focuses on volcanic gases as a way to monitor volcanic activity and its impact on the environment and the atmosphere. And, it turns out, volcanic gases are rather important when it comes to attempting to understand these mountainous pressure pots.

Evgenia - They can first of all tell us what is happening underneath the volcano. They can tell us whether molten rock or magma, as we call it, is moving towards the surface. If there’s fresh magma being injected into the volcano. Once an eruption starts, we can use the gas to measure how big the eruption is. If it’s becoming smaller and so on and so forth.

Some of the most abundant gases in magmas are actually water, carbon dioxides, and then sulphur dioxide. Sulphur dioxide is something that you might hear volcanologists talk about a lot. It’s a very important gas because it’s relatively easy to measure but it also has quite important environmental implications because it can be quite toxic.

Izzie - Now sulphur is a complicated beast and can exist in many forms. In volcanoes it comes out as hydrogen sulphide, which actually smells like rotten eggs, or more commonly sulphur dioxide, which is acidic. It can sting your throat, your nose, and your eyes and is definitely something to avoid. Plus, it takes its toll on the environment…

Evgenia - If people remember the London pea soup fog back in the 1950s, that was actually caused by sulphur dioxide which was being emitted by coal burning power plants, but volcanoes definitely emit this. We can visually see it in the atmosphere; it sort of tends to be a blue, brown, grey cloud and you can really see impacts on vegetation, so not a lot of plants can survive in this kind of environment.

Sulphur dioxide can impact climate. It tends to happen in very very big explosive eruptions. So think about the Pinatubo eruption in the Philippines in 1991 or El Chichon eruption in South America in the 80s. These are huge eruptions and the eruption column goes up to tens of kilometres up in the stratosphere, so higher up than planes even fly. If that happens, gases, in particular sulphur dioxide, can stay up in the atmosphere for very long periods of time, so months or years, and in those scenarios we can start to see climate impacts around the globe.

Actually what happens is that sulphur dioxide with time in the atmosphere gets converted into tiny tiny particles, and those particles reflect incoming solar energy making the climate actually cooler than it was before. Living organisms that are very sensitive to small changes in temperature will react differently or habitats can start to change if it’s a really long lasting effect.

Izzie - Carbon dioxide is also released in a volcanic eruption and we hear so much about it in the news. So could this be having an affect on climate change?

Evgenia - Carbon dioxide is one of the very common gases in volcanic emissions, and it is a greenhouse gas which means overall it would warm the planet. And that is a reason our planet is warming at the moment is because human activities are producing so much carbon dioxide. In comparison to how much human activities are producing, volcanoes are producing actually very very little carbon dioxide, something like only 2 percent.

Izzie - Ah right. So we’re causing more damage then. But is there any way we can use volcanoes to our benefit?

Evgenia - It’s very important to remember that volcanoes are not just destructive forces. While volcanoes produce some carbon dioxide they can actually be used to capture carbon dioxide, so removing it from the atmosphere and thereby reducing the effect on climate that humans are having. This is something that is being experimented on in Iceland very successfully where they’re taking carbon dioxide out of the atmosphere and pumping it back into the volcanic rock and making it stay there.

Another very interesting way of possibly using volcanoes is people tend to like living on volcanoes because volcanic soils are quite fertile. And also in hotter countries, living up on the flanks higher up on the volcano means that the climate is a lot more pleasant, and a lot of plants are grown high up on volcano flanks. For instance coffee is produced in a lot of countries with active volcanoes.

Izzie - And that’s not all. Volcanoes produce a lot of power and this can then be used to heat homes and water for those nearby.

Evgenia - Geothermal energy works when you have heat coming from molten rock deep down in the ground that is heating groundwater around it and this groundwater can be several hundreds of degrees hot. This superheated steam can be taken out of the ground and piped to communities and either just be used to then heat cold water for showers etc., or to drive steam turbines to generate electricity. It’s fantastic to see this where it’s well set up. In Iceland, something like nine out of ten homes are heated entirely by geothermal volcanic energy. Energy like this is very very cheap.

Of course volcanoes, we can only use very little percentage of the energy that volcanoes are able to generate so there’s a lot more to do with volcanoes and discover how we can harness the energy much better.