Volcanoes are one of the most powerful forces on Earth and it is becoming increasingly clear that these forces are being altered by climate change.
Declining ice cover can trigger more frequent eruptions near the poles, in Iceland and other places. Also, an increasingly layered ocean will allow more volcano induced cooling to linger at Earth’s surface. A new study suggests increased greenhouse gases will help the plumes from large eruptions reach higher, spread faster and reflect more sunlight, causing more abrupt and extreme cooling.
Before human induced climate change, volcanoes were one of the biggest sources of climate change. Over the long term, they spewed out carbon dioxide from Earth’s interior, causing warming. However, in the short term, their sulfur gases often react with water to form highly reflective particles called sulfates, triggering phases of global cooling.
But a new study shows that the opposite is also true: climate can have a big impact on volcanoes. The researchers found two trends. Normally just one or two midsize volcanic eruptions shoot through the troposphere each year, to reach the stratosphere, the calm,dry zone above. As reflective particles spread through the stratosphere, they cause a small amount of global cooling. But when the troposphere warms, it expands in height, which eventually puts the stratosphere out of reach of these eruptions.
https://www.sciencemag.org/news/2021/08/massive-volcanoes-could-cool-earth-more-warming-world