Do volcanoes contribute to global warming?
The short answer is ‘no.’ An erupting volcano throws huge clouds of particles and gases into the atmosphere. One of these gases, sulphur dioxide, is highly reflective, and will actually scatter and reflect the sun’s rays, thus decreasing the amount of energy reaching the Earth and causing short-term global cooling. However, not all volcanic eruptions, and not even all large eruptions, produce global-scale cooling. Whereas the eruption of Mt. Pinatubo in the Philippines in 1991 brought about global cooling of up to 0.3 degrees C lasting for up to two years, the eruption of El Chichon, in Mexico in 1982, had little effect. The difference might be in the location of the volcano, or in worlwide weather variations.
