Volcanoes, Climate Change, and Sustainability

Abstract

Volcanoes have a complex relationship with sustainability and climate: they contributed to the formation of Earth’s atmosphere, can have short-term effects on local climate and world climate, and have been used as a scapegoat for man-made climate change. A better understanding of volcanoes and their relation to climate provides students with a more nuanced view of their environment, specifically climate change. By interesting students in environmental science, one hopes that their fascination leads to greater investment in the sustainability of their local environments.

1 Introduction to the Participants

I (Sedelia) was originally trained as a geologist. I study rocks that solidified from magma or lava to decipher how these formed. I think that teaching students about the natural world is especially important because hopefully as they look more at their environment, they will appreciate it more and want to preserve it. Knowing what happens naturally helps plan for a sustainable community. We cannot control everything. What are some things we cannot change? What do we need to work around? When you do not understand the natural world, it is harder to fight for it. Knowledge about the environment becomes a vehicle for activism.

I (Kassandra) am a student. I interviewed Professor Rodriguez about how she integrates her interest in volcanoes into her teaching in a way that is inclusive.

Kassandra

What courses do you teach where you talk about volcanoes?

Sedelia

Today, I will focus on my teaching of a First-Year Seminar, but I try to integrate volcanoes into all of my teaching, including Introduction to Environmental Science. The First-Year Seminar is not a science course, the focus is on writing and speaking. We want students to gain their voice and speak confidently. So I had to think about how to introduce science in this type of setting when students do not have a strong scientific background or potentially even a scientific interest. Some of the ways I do this is by getting them to relate to some aspect of a volcanic eruption—how volcanoes affect climate and agriculture (and therefore societies), tourism, etc. After that, I talk about hazards and volcanic eruptions, and now they are interested because they know the information is relevant. Pop culture helps to make volcanoes relatable and I use that as a tool for student engagement. Also, I do not start lecturing about the science of volcanoes, but rather introduce it slowly throughout the semester. The whole point is to get students interested and for them to see the information as relevant to their own lives.

Kassandra

In your experience, students do not initially see volcanoes as relevant to their own lives?

Sedelia

Most of my students do not live near volcanoes and, therefore, do not realize the effects that volcanoes can have upon their lives. I had a student come up to me at the beginning of the semester and insist that, because she was not a science major nor did she have any connection to volcanoes, the course was not relevant or interesting to her. I try to show students why they should care. I talk about the effects that volcanoes may have on their lives and the lives of others, in an inclusive way. In some cases, people who live around volcanoes are Indigenous farming populations. I also discuss how air travel disruptions may affect students while traveling even if they do not live near a volcano. I talk about how ash erupted during a volcanic eruption can have health effects on those living near volcanoes, especially those with respiratory problems. And if a Supervolcano were to erupt, such as Yellowstone in the United States, ash could be distributed all over the country, affecting those who live far away from a volcano. We also discuss how crops can be affected by eruptions; nowadays we get fruits and vegetables from all over the world, so an eruption can affect the production of different foods and items. By getting students to connect volcanoes to their own lives, I hope to engage and interest them in a topic they may never have thought about before.

Other students have grown up near areas of volcanic activity; for example, last year I taught students from Ecuador, Mexico, Seattle, and Northern California. The student from Ecuador shared her experiences seeing smoke and ash fall over her city and having to wear a mask to protect against the ash. She also mentioned that people in lower-income areas had fewer resources and were therefore affected more by the eruption. In some cases, stores and businesses were closed for weeks, which directly affected this population. She was able to see the socioeconomic discrepancies and injustices in her country when a natural disaster occurred. Her stories fascinated other students and made them more interested in volcanoes.

I also noticed that the students from volcanic areas developed an authentic eagerness to further investigate their local volcanic activity. I had my students research a volcanic area, and the students who grew up near volcanoes researched their local areas. The student from Mexico had grown up hearing stories about the volcano near her home. After learning more about volcanoes, she wanted to hear all of the old stories from her grandmother and became excited to research her local history. The student from Seattle researched the possible dangers of Mount Rainier and learned about evacuation plans. And, the student from Northern California researched an area near her home where geothermal research was occurring. She had been there before but had never known about the research happening. She was so excited to learn about geothermal energy and vowed to visit the area again when she visits home.

Kassandra

We have seen a lot of destruction by volcanoes in the news, with eruptions from Kilauea in Hawaii, beginning in April 2018, and the eruption of Volcán de Fuego in Guatemala on June 3, 2018. How significant of a threat do volcanoes pose to humans?

Sedelia

For those who live in the vicinity of a volcano, the destructive impact can be significant. Strato or composite volcanoes such as Volcano del Fuego tend to be very destructive due to the high silica content of the magma, which affects the viscosity, temperature, and amount of dissolved gases. Higher viscosity, lower temperatures, and more gases result in more explosive eruptions. After a large eruption, like the one in Guatemala, a wave of heat, ash, and wind explodes from the volcano with hurricane strength. This is a pyroclastic flow, the most destructive aspect of a volcano, and, if one is near the explosion, there is no way to outrun it. Lahars, which are mudflows generated by a volcano, come very suddenly after an eruption and have buried entire towns without warning. Earthquakes also often accompany an eruption, although they sometimes serve only as precursors, providing warning signs of rising magma. Ash flow, a mixture of gas and fine-grained rock fragments ejected from the volcano, can cause health problems, especially for those with asthma or other breathing difficulties. Volcano ash can also shut down air traffic, leaving people stranded while traveling and causing economic consequences.

For example, in 2010, after the eruption of Eyjafjallajokull in Iceland, there was an air traffic shut down in parts of Europe between April 15 and May 16. It affected areas as far away as the United Kingdom, France, and some of Germany. Lava flows typically cause very few fatalities because they move so slowly, but they can cause great destruction to crops and buildings. The eruption of Volcán de Fuego spewing ash and lava resulted in 200 deaths. In the case of Volcán de Fuego, the eruption came very suddenly, and the public insists that they were not urged to evacuate, although government officials say otherwise. The eruption destroyed corn, bean, and coffee crops, a total of 21,000 acres of crops.¹ This obviously has a negative effect on the nearby population, both as their food resources are destroyed, but also an economic one because they cannot sell their crops. The infrastructure, roads, bridges, etc. were also destroyed, leaving many stranded.

When Kilauea erupted in Hawaii, many people lost their homes and the island suffered significant damage to infrastructure. However, no deaths were reported in Hawaii because residents had adequate time for evacuation. The Hawaiian volcanoes have less explosive eruptions due to their chemistry. Scientists have warning systems that track precursors to eruptions, such as earthquakes. Although it can be difficult to predict the precise day or even month of an eruption, when they notice an increase in earthquakes for example, they put up a warnings and begin evacuations.

Sometimes, even when the warning to evacuate does come, people refuse to leave. Some cultures carry beliefs about the godlike nature of volcanoes, believing that eruptions serve as a form of divine retribution. In certain islands of Indonesia, people refused to leave their homes during times of increased volcanic activity, believing that if they prayed and gave offerings, they would be saved. The unwillingness to leave one’s home is logical to an extent. To evacuate means to abandon everything they have ever known and often one’s livelihood, which can seem too large a price when volcanic eruption predictions are often inaccurate. Even in Hawaii, some residents did not want to leave their homes and were skeptical of the danger. It is necessary that we learn to coexist with volcanoes and continue to improve methods of eruption prediction because, despite the danger and destruction, volcanoes provide tremendously beneficial services for the environment and for humans that live around them.

Volcanic-rich soils allow for crops to flourish, which is one of the reasons why people live close to volcanoes.² For example, many crops are grown near the base of Vesuvius in Naples, Italy. Farmers in the area attest to the unique flavor of their grapes, tomatoes, and wine due to the rich volcanic soil. Volcanoes also form new land; the recent eruptions in Hawaii formed an entire mile of new land. Volcanoes provided beneficial gases early in Earth’s history to create a greenhouse effect, which warmed the planet Kay & Fuiten (this volume) and added amino acids to the Earth’s surface. The release of these gases allowed for life to develop. We need a greenhouse effect to stop too much solar radiation from coming down to the surface of the Earth. This is just one way that volcanism is related to climate change.

Kassandra

Do you think students are interested in climate change?

Sedelia

Oh definitely, my own son was already being taught about climate change in the first grade. I think that students nowadays are so aware of it—they might not look into it too much, but they know enough to be concerned. They are also aware that certain areas, for example, low-income neighborhoods are affected more by the changes in climate and pollution.

Kassandra

What effect do volcanoes currently have on Earth’s climate?

Sedelia

Historic eruptions by stratovolcanoes have had short-term effects on Earth’s climate with effects waning within a few years. These volcanoes typically cause cooling effects. For example, in 1991, the eruption of Pinatubo in the Philippines lowered global temperatures by about one degree Fahrenheit. Within 2 years, the temperature returned to normal. Most volcanic eruptions do not affect the global climate significantly. Generally, an eruption has to be very large to have a global impact. Additional factors contribute to climatic changes, these include, the volcano’s location on Earth, where equatorial eruptions have been known to travel across the globe, and plume material has to reach the Earth’s stratosphere to effectively disperse sulfur aerosols globally. Most volcanoes do not have any effect on climate, even in the short term.³

Kassandra

Do volcanoes play any role in climate change? In other words, how valid is the argument that volcanoes contribute as much or more to climate change than human activities like burning fossil fuels or deforestation?

Sedelia

Some people will say that volcanoes emit greenhouse gases (CO₂, methane) that could affect our climate. However, the amount of gases emitted by volcanoes on a yearly basis is not nearly enough to cause the climate change that has already happened in recent decades on Earth. Volcanoes that have been monitored recently and in the near past have not shown any levels that would contribute to global warming. Airplanes have more carbon dioxide emissions than volcanoes do today. Prehistoric eruptions, such as flood basalts, on the other hand, have been linked to mass extinction events. During these events, global climate has been affected significantly, many times leading to warming periods. In addition, we have seen ocean acidification conditions and tremendous loss of both flora and fauna.

Kassandra

What’s the big difference between the volcanic eruptions that occurred early in Earth’s history and had such a strong impact on climate versus the more recent volcanic eruptions that have little effect on climate?

Sedelia

As I mentioned earlier, in the Earth’s past, it has had large igneous provinces or flood basalts eruptions, which are large eruptions of lava in relatively short periods of time, most of which formed large plateaus over much more extensive areas of land as compared to much more localized impacts of contemporary active volcanoes. A great example of these is the Siberian Traps.⁴ This continental flood basalt eruption was the largest eruption event in the history of the Earth. Approximately 4 million cubic kilometers of lava erupted within a million years, a short period of time, geologically speaking. Other researchers and I are looking into the effects of the Siberian Traps because, coincidentally, one of the largest extinction events that we’ve seen occurred around the same time. We haven’t seen this type of massive eruption for about 17 million years, since the Columbia River Basalts erupted. This eruption covered parts of Washington, Oregon, Idaho, and Nevada. It would take one of these huge eruptions to significantly impact climate on a global scale. In other words, we can’t blame volcanoes for our current global crisis but we can learn about their effects in order to mitigate future disasters.

Kassandra

How can volcanoes help cool the climate?

Sedelia

When volcanoes erupt, they emit plumes of gases, ash, and rock. These gases, if erupted high enough into the stratosphere, can react to form aerosols. Sulfur dioxide (SO₂) in particular can form aerosols that can block some sunlight from reaching the Earth’s surface. This creates a cooling effect. Some scientists have proposed monitoring the next volcanic eruption closely to see what happens to SO₂ in the atmosphere before and after it mixes with water vapor to form aerosols. They also have proposed artificially injecting the atmosphere with such gases or other materials that reflect sunlight in order to slow down global warming.⁵ But, the idea is very experimental. Most scientists disagree with these methods of geoengineering because we do not know what the side effects would be of doing this.

Kassandra

How does this process work, more specifically?

Sedelia

What they would do is fly a plane up to the stratosphere and release different particles that can reflect sunlight, just like sulfur aerosols do. These particles would theoretically block sunlight, allowing the Earth to cool. It would obviously have to be a very large area to have a significant impact on the Earth’s temperature. This is known as solar geoengineering.⁶

Kassandra

What are the ethical considerations concerning solar geoengineering?

Sedelia

The big concern is that we don’t know what the unintended consequences of releasing these particles would be. Could there be chemical reactions in the atmosphere that we did not anticipate? How would this affect people, animals, and vegetation around the world? Would there be changes in weather patterns, decreased rainfall, or would this process destroy the ozone layer (SO₂ aerosols) and warm the stratosphere? In addition, there could be an unexpected “runaway” effect Kay & Fuiten (this volume) if the process could not be stopped. Even if scientists are careful and conduct small-scale experiments, they cannot account for the long-term, large-scale side effects that could have world-wide consequences. Finally, this process does not reduce CO₂ emissions and some scientists worry that some governments would focus on this method instead of continuing to reduce CO₂ emissions. There are just too many uncertainties at this time.

Kassandra

You mentioned in an earlier conversation that you talk about geoengineering with students in your seminar. How can asking students to debate the costs and benefits of geoengineering allow them to connect more deeply with the course material?

Sedelia

Geoengineering is something that could definitely affect them since this would be a global event. The students in my class were already concerned about climate change, therefore contemplating the effects of such an endeavor made them think “wow, this could affect me or my family or my home directly.” They were very animated and opinionated about this, and most of their opinions about geoengineering were negative.

Kassandra

Since you’re teaching a First-Year Seminar, do you ever hear about students using what they learned in later classes or in their communities?

Sedelia

The connections that students make between their own experiences and their coursework can have a profound impact, both on the students and their local environments. One particular student, after studying geology, found out that the area where she went camping as a child, has rocks that are ideal for carbon sequestration (Baxi et al., this volume). She went back and studied these particular rocks for her senior thesis project and looked into the possibility of doing some carbon sequestration in that area. After graduating, she moved back to her hometown and is now teaching about the geology of the rocks among other topics at an elementary school in the area. This student’s experience and interests prompted her to explore intellectually and do something beneficial for her environment and community. That is the power of tying students’ learning to their lived experiences.⁷ I want my students to learn for the sake of learning and possess an authentic curiosity about the world, but I also hope that they take this knowledge and do something beneficial with it, especially considering current environmental issues.

Kassandra

Why do you think it is important for your students to draw a connection between sustainability, climate change, and volcanoes?

Sedelia

In order to truly understand climate change, one needs to understand the Earth. A multitude of factors influences climate change: ocean circulation, solar heat, sun spots, arctic winds, tectonic plate movement, and volcanoes. Some of these factors influence short-term climate change, such as volcanoes, whereas others, such as tectonic plate movement, influence long-term change over millions of years. All of these factors interact with one another in complex ways and the effects of each can be difficult to separate from one another. These complex interactions make it incredibly difficult to create accurate models; when any of the factors fluctuate unexpectedly, it can throw off the model. And, because there are so many natural factors, climate change skeptics can easily blame the influence of natural factors on our current accelerated climate change. A thorough understanding of the Earth provides one with the power to respond to skeptics and recognize the difference between natural and man-made climate influencers. In order to understand the Earth—and how to live sustainably with it—one needs to understand the science and its history, and volcanoes can provide much of that information.