Recent research by environmental scientists has sparked new conversations on the relationship between volcanic eruptions and global warming. While it’s a fact that volcanic activity can contribute to surface level climate changes, the scale of influence on the overall global climate is far from clear. The limited research and mixed scientific opinions on the matter have raised questions about the direct or indirect links between volcanoes and rising temperatures, as well as what impact this may have on future climate change.
Over the last decade, scientists have made some substantial discoveries about the role volcanoes can play in climate change. It’s been observed that small to moderate eruptions can emit several problems into the atmosphere, including dust, sulfur dioxide, water vapor, and gases such as carbon dioxide and halogens. These particles can travel hundreds of miles and even create a thin, opaque layer in the stratosphere that blocks out some solar light and causes cooling at ground level. In fact, an eruption of Mount Pinatubo in the Philippines in June 1991 was estimated to have caused a 0.6 to 0.9 degree Celsius drop in global temperatures over the following 18 months.
However, findings have been inconclusive for larger eruptions and the long-term impacts these may have on global temperatures. Historical data from some of the world’s largest eruptions, such as Tambora in 1815, suggest that they can cause surface level cooling of several degrees Celsius over the following years, counteracting the warming caused by greenhouse gases.
This has caused many to raise the question of whether solar-blocking effects from larger eruptions can counteract steady global warming, at least in the short term. However, several variables must be taken into consideration. While the ash and aerosols emitted by the eruption can create a cooling effect, they also tend to linger in the atmosphere for around 3 to 5 years. Within this timespan, they absorb radiation, causing warming that can outstrip cooling at ground level. This warming effect could be further impacted by the amount of carbon dioxide released from the eruption, which acts as a long-term greenhouse gas with well-documented warming effects.
Experts have mixed opinions about some of the complexities of volcanic eruptions and global warming, with some arguing that the overall cooling effects far outweigh those of ongoing greenhouse gas emissions. An analysis from MIT suggests the total cooling effects of a Tambora-type eruption could be 3.2 watts per square meter for up to 5 years, while research from the Department of Earth and Space Sciences at the University of Washington puts the figure as high as 5.3 watts per square meter. This is more than double the output of greenhouse gasses and aerosols released by human activities, proving that while volcanic eruptions can cause cooling, they can also cause significant warming.
A recent trial carried out by meteorological scientists suggests that volcanic eruptions that send dust and aerosols high into the stratosphere can actually shift heat patterns on Earth and interfere with typical weather patterns. This suggests that more research into how volcanic eruptions interact with larger global climate systems is needed. Therefore, when describing the impact of volcanic eruptions on global warming, it’s important to consider both the cooling and warming effects and look at the longer-term impacts, rather than just focusing on the initial cooling.
Volcanoes can have both positive and negative effects on global temperatures and climate in the long run. While, comparatively, eruptions may cause cooling at ground level, they can also potentially smooth out existing weather patterns and, over time, be an additional source of greenhouse gases. Ultimately, it appears that, while more research is needed, volcanic eruptions are not likely to be major contributors to global warming in the short term, but could become more of an influence in the longer term.
As the research on volcanos and global warming evolves, scientists and policy-makers must examine the long-term effects and observe methods for predicting, preventing, or mitigating their impacts. By working together, it’s possible to develop strategies for studying the effects of volcanic eruptions, and in turn, reduce the risks posed by global climate change.
