http://denali.gsfc.nasa.gov/research/so2/article.html http://denali.gsfc.nasa.gov/research/so2/article.html http://denali.gsfc.nasa.gov/research/so2/article.html Pinatubo cooling due to volcanoes Global Effects of Explosive Volcanism cooling due to volcanoes a large load of sulfur dioxide a large load of sulfur dioxide