Question

How do volcanoes affect the climate on earth?

Answer 1

If they are high ash volcanoes, they tend to cool the planet for a few years. If they are high CO2 emitting volcanoes that erupt for decades, they can warm the planet.

Explanation:

High ash volcanoes, typically like those along the west coast of North America, when they erupt tend to deflect incoming radiation from the sun so that it doesn't reach the earth and consequently, the planet cools for 2-3 years. But not enough to put us in another ice age. If the volcano or volcanic fissure is high in CO2 and if it lasts for decades or hundreds of years, it can pump a lot of CO2 (a greenhouse gas) into the atmosphere. This in turn strengthens the greenhouse effect and warms the planet.