Currently, the classification of the maximum magnitude of a volcanic eruption is of the order of 8, according to the volcanic explosivity index (VEI). Each IEV unit corresponds to a process that increases on an exponential scale of ten, considering: the height of the eruptive column, the duration in hours, the elements of qualitative appreciation and the volume of expelled material.
The volcanic eruption of Tonga released more energy than the most powerful nuclear bomb ever dropped.
The volcanic eruption of Mount Tambora, located in Indonesia, it reached a magnitude of 7 in 1815, killing about one hundred thousand people. This has raised awareness of the need to monitor volcanoes, but we are still a long way from preventing a super eruption and allowing the population to emerge unscathed from this scenario. Few investments are made to mitigate the consequences of an eruption of this magnitude. Imagine it’s bigger than that!
In January 2022, the Hunga Tonga-Hunga Ha’apai volcano erupted with an intensity of 6 on the IEV scale, spitting ash that has reached the stratosphere of planet Earth. Iceland’s Fagradalsfjall volcano erupted last month with a magnitude of 5.4 on the IEV scale.
An article published in August 2022 in the journal Nature states that the intervals between catastrophic eruptions are thousands of years shorter than previously thought; points out that it is wrong to say that the risks of major eruptions are low and calls the lack of investment by governments in monitoring and responding to potential volcanic disasters “reckless”.
According to the authors, in the following century, Large-scale volcanic eruptions are hundreds of times more likely than asteroid and comet impacts. Frustrating, because while “planetary defense” benefits from the commitment of several agencies around the world and receives millions of dollars in funding, the same is not true for volcano studies.
The world is not prepared for such events, said Professor Michael Cassidy of the Center for the Study of Existential Risk at the University of Cambridge.
Recent data on ice cores suggest that the probability of a magnitude 7 major eruption on the IEV scale is 16% for this century. Eruptions of this size have already caused abrupt climate change and the collapse of civilizations, as well as being associated with an increase in pandemics, the researchers say.
There are no coordinated actions or major investments to mitigate the global effects of volcanic eruptions. According to the scientists, it is essential to devote more means to monitoring volcanoes, especially aerial and satellite observation and soil monitoring.
It is scientifically evident that volcanoes emit less carbon dioxide than anthropogenic activities. But the increased frequency of intense volcanic eruptions, coupled with the acceleration of human activities, will have a negative impact on the process of climate change. Not to mention the other social consequences of the damage caused by volcanic eruptions.
How volcanoes can affect the climate
During larger eruptions, large amounts of volcanic gases, aerosol droplets and ash are injected into the stratosphere. Most of these substances are removed from the upper atmosphere within a few weeks. But gases like carbon dioxide (a greenhouse gas and the main driver of climate change) can promote global warming.
There is therefore no doubt that very large volcanic eruptions can inject significant quantities of carbon dioxide into the atmosphere, thus contributing to the process of intensification of climate change. Furthermore, sulfate aerosols have the ability to destroy the earth’s ozone layer.