Volcanic eruptions are powerful natural phenomena which have been active on earth for centuries, and their potential effect on global warming and climate change have come up for debate in recent years. Compared to other sources of atmospheric pollutants, the contribution of volcanoes to global warming is relatively small, though their eruptions can produce significant levels of carbon dioxide and other greenhouse gases. However, it’s important to consider the implications of volcanic activity in order to get a full understanding of how we can reduce future global warming.
Immediate emission of greenhouse gases, primarily carbon dioxide, during explosive volcanic eruptions can contribute to climate change in the short-term. For instance, the 1991 eruption of Mount Pinatubo in the Philippines was the second-biggest volcanic eruption of the twentieth century, and it triggered global cooling of about 0.5°C for at least a year. On the other hand, the emission of carbon dioxide from relatively less explosive volcanic eruptions, such as those of the Kilauea volcano in Hawaii, is a more sustained process that can add to the already existing impact of human activities on climate change. According to recent estimates by researchers at the Hawaii Institute of Geophysics and Planetology, this type of eruption may have currently released over 5,000 tons of carbon dioxide into the atmosphere.
These emissions are not the only impacts volcanoes have on the global climate. Volcanic eruption clouds also cause changes in the amounts of solar energy received by the Earth. Just after the Mount Pinatubo eruption, the aerosols and tiny droplets of sulfuric acid generated by the eruption reduced average temperature by as much as 2°C, as they reflected solar energy before it could enter the atmosphere. While this effect is usually short-lived, pronounced volcanic activities can lead to marked cooling periods.
In addition, an increase in concentrations of sulfur dioxide and halocarbons in the atmosphere following a volcanic eruption might contribute to ozone layer depletion and global cooling. In contrast, the release of chlorofluorocarbons profoundly enhances ozone production, resulting in more solar radiation reaching the Earth and higher global temperatures. This was the case with the Laki volcanic fissure in Iceland in 1783, which caused global warming of as much as 5°C.
In conclusion, the potential of volcanic eruptions to contribute to global warming is complicated and includes short- and long-term impacts, as well as both cooling and warming effects. Ultimately, it’s important to comprehend these dynamics in order to help inform the mitigation of future climate change. This can be done through a larger investment in research and collaboration to create a better understanding of the type of volcanoes that can lead to long-term global warming.
