CO2 from volcanos

According to the U.S. Geological Survey (USGS), the world’s volcanoes, both on land and undersea, generate about 200 million tons of carbon dioxide (CO2) annually, while our automotive and industrial activities cause some 24 billion tons of CO2 emissions every year worldwide. Despite the arguments to the contrary, the facts speak for themselves: Greenhouse gas emissions from volcanoes comprise less than one percent of those generated by today’s human endeavors.

Furthermore, some scientists believe that spectacular volcanic eruptions, like that of Mt. St. Helens in 1980 and Mt. Pinatubo in 1991, actually lead to short-term global cooling, not warming, as sulfur dioxide (SO2), ash and other particles in the air and stratosphere reflect some solar energy instead of letting it into Earth’s atmosphere. SO2, which converts to sulfuric acid aerosol when it hits the stratosphere, can linger there for as long as seven years and can exercise a cooling effect long after a volcanic eruption has taken place.

Scientists tracking the effects of the major 1991 eruption of the Philippines’ Mt. Pinatubo found that the overall effect of the blast was to cool the surface of the Earth globally by some 0.5 degrees Celsius a year later, even though rising human greenhouse gas emissions and an El Nino event (a warm water current which periodically flows along the coast of Ecuador and Peru in South America) caused some surface warming during the 1991-1993 study period.