Volcanic ash can travel several hundreds or thousands of kilometers and can disrupt air traffic.
The global economy can then be impacted for weeks or months.
The gases and finest particles of ash can partially obscure sunlight around the globe, causing the Earth’s temperature to decrease for several years
It is said that the eruption of the Laki volcano (Iceland) in 1783, changed the planet’s climate and would have caused crop failure and famines throughout Europe. This eruption would have thus played a role in the French Revolution!