NEW TPO 8 What does the speaker imply about volcanoes and global warming?

[00:00.00][00:00.24] Listen to a talk in a geology class.
[00:01.00][00:04.25]Today, we’re going to discuss volcanoes. When a volcano erupts, it releases a variety of gases and particles into the atmosphere.
[00:02.00][00:07.77]Volcanic ash falls out of the atmosphere in a matter of days or weeks and has little effect on the climate.
[00:03.00][00:21.97]One of the most significant gases entering the upper atmosphere is sulfur dioxide, which forms substances called sulfate aerosols there.
[00:04.00][00:33.09]These aerosols reflect sunlight away from the Earth, leading to a cooling effect on the planet’s surface.
[00:05.00][00:40.89]This phenomenon was observed after one of the largest volcanic eruptions in the twentieth century, the eruption of Mount Pinatubo in 1991.
[00:06.00][00:50.48]Pinatubo’s eruption caused a temporary global temperature drop of about half a degree Celsius.
[00:07.00][00:56.92]However, not all volcanic eruptions have the same impact on the climate.
[00:08.00][01:01.84]The extent of the cooling effect depends on several factors, including the magnitude of the eruption, the amount of sulfur dioxide released, and the location of the volcano.
[00:09.00][01:14.31]For instance, because of atmospheric circulation patterns that spread gases around the world, eruptions near the equator tend to have a bigger effect on the global climate than eruptions elsewhere do.
[00:10.00][01:26.91]Additionally, the cooling effect is typically short-lived, lasting only a few years before the aerosols settle out of the atmosphere.
[00:11.00][01:36.39]Volcanic eruptions can also contribute to longer-term climate change through the release of carbon dioxide, a gas that contributes to global warming.
[00:12.00][01:46.65]It must be remembered, however, that human activity releases far more carbon dioxide into the atmosphere than is released by volcanic eruptions.