How do volcanoes influence climate?

Question

thanks (:

Answer 1

If a particularly destructive volcanic eruption occurs like Krakatoa or perhaps Mt. Pinatubo, the ash cloud can rise up to many miles into the Earth's atmosphere and spread out from the area into thousands of miles away, creating long winters and odd-colored sunsets around the world. Check out Wikipedia's Krakatoa and Pinatubo pages to see what I mean.

Answer 2

Volcanoes can both warm and cool the earth-

Volcanoes emit a very large amounts of sulfur compounds (sulfur dioxide, sulfur oxide), which tend to affect the atmosphere more than normal 'dust' that you find everyday.  These compounds reflect solar radiation, therefore cooling the earth.

But volcanoes also emit many tonnes of CO2 which warms the earth.  

Generally, the short-term effect of an eruption is to cool the earth.  But since eventually the dust compounds precepitate out of the atmosphere, the remaining CO2 is still in the atmosphere.  Volcanoes emit about 110 million tonnes of CO2 per year.  Humans create about 10,000 times more than that (or about 1.1 trillion, if my math is correct)

Answer 3

The ash from the volcano stays suspended in the upper atmosphere and blocks the sun's rays. Also, the same ash can become a precipitate for rainfall, much the same way they seed clouds to encourage rainfall.

So it gets dark. It gets cold. It gets rainy.