Figure 19-1 An enormous cloud of air pollutants and ash rises above Mount Pinatubo
in the Philippines on June 12, 1991. The volcano exploded in a catastrophic eruption,
killing hundreds. Sulfur dioxide and other gases emitted into the atmosphere by the
eruption circled the globe, polluted the air, reduced sunlight reaching the earth’s surface,
and cooled the atmosphere for 15 months.