Explosive eruptions can cause substantial cooling of global surface temperatures, lasting for anywhere between1to 10 years. We have known about this cooling for centuries, with our temperature records often showing distinct dips following major eruptions.
One of the clearest examples of this was the 1815 eruption of Mount Tambora, an explosive event that caused a 1°Cdrop in global land temperatures. The eruption was so energeticthat volcanic gases were injected into the stratosphere, the layer of the atmosphere 10to50km above the surface. This caused incoming sunlight to be blocked, meaning that not as much reached theEarth’ssurface.
While more explosive volcanoes tend to cause more global cooling,it’s not always the case. It depends on the ejected gases reaching the stratosphere, and on wind systems. Mount St Helens, one of themost violent eruptions of modern time, hardly made a dent in globaltemperatures due toitsgases not persisting in the stratosphere.
Could volcanic eruptions mitigate the increased temperatures from climate change? Unfortunately not. Volcanic eruptions have occurredoverhistory and are a natural component of our atmosphere. Their effect is also short-lived, with surface cooling from eruptions lasting a matter of years,whilesurface warming from excessive carbon dioxide emissionslasts for thousands.
Read more:
- What would happen if all volcanoes on Earth erupted at once?
- The thought experiment: What would happen if the supervolcano under Yellowstone erupted?
- Why is the Gulf Stream slowing down and what does it mean for the future of the UK’s climate?
- Can planting billions of trees help tackle climate change?
Asked by: David Scott, Port St Mary, Isle of Man
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