Is Natural Pollution A Hoax?

Volcanic eruptions are one of the most commonly cited sources of natural pollution. Consequently, “Volcanoes produce far more carbon dioxide emissions than humans do!” is a common rebuttal used to justify the copious amounts of carbon dioxide (CO2) that human activities pump into the atmosphere. Is volcanic pollution truly worse for the atmosphere than anthropogenic pollution?

Well, in terms of carbon dioxide, not quite.

According to the US Geological survey, the world’s volcanoes emit about 200 million tons of CO2 annually, compared to a staggering 24 billion tons of CO2 emissions contributed by anthropogenic automotive and industrial activities [1]. Evidently, volcanic eruptions account for a minute fraction of the total annual CO2 emissions injected into our atmosphere. On the contrary, volcanos may actually contribute to the aerosol cooling effect discussed in the last blog post! This is owing to how sulphur dioxide, ash, and other particles can act as aerosols to reflect incoming solar radiation, thereby reducing temperatures in a phenomenon known as “volcanic winters” [2].

However, volcanic pollution is not really a “hoax”, since volcanic eruptions do contribute to CO2 emissions, just on a relatively much smaller scale as compared to humans. Additionally, other chemicals from these eruptions, including sulphur dioxide, hydrogen fluoride, water vapour, and ash, have adverse effects on atmospheric and human health. For instance, sulphur dioxide contributes to acid rain and damages the ozone layer, whereas ash is destructive to landscapes, reduces visibility and can cause severe breathing problems [3],[4].

Additionally, volcanic eruptions tend to present a type of transboundary atmospheric pollution problem since the emissions from volcanic eruptions may disperse far away from the site of eruption owing to air circulation. For instance, in 1883 the eruption of Krakatau in Indonesia outgassed aerosols  that dispersed all the way to New York [5]. Therefore, issues such as this require nations to coordinate beforehand for adequate monitoring and emergency response strategies. Rather than using volcanic pollution as a scapegoat for anthropogenic CO2 emissions, attention must be redirected towards mitigating the catastrophic effects associated with eruption events and devising strategies to deal with such international pollutants in a just and equitable manner.

[1] Volcanoes Can Affect Climate | U.S. Geological Survey. Www.usgs.gov. https://www.usgs.gov/programs/VHP/volcanoes-can-affect-climate

[2] Are Volcanoes or Humans Harder on the Atmosphere? (2009). Scientific American. https://www.scientificamerican.com/article/earthtalks-volcanoes-or-humans/

[3] National Geographic. Human and Environmental Impacts of Volcanic Ash | National Geographic Society. Education.nationalgeographic.org. https://education.nationalgeographic.org/resource/human-environmental-impact-volcanic-ash

[4] US EPA, O. (2013, June 3). Volcanoes. US EPA. https://www.epa.gov/natural-disasters/volcanoes#:~:text=Volcanic%20gases%20that%20pose%20the

[5] Volcanic Pollution. (2014). Cuny.edu. https://intlpollution.commons.gc.cuny.edu/volcanic-pollution/

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