David Keith was a graduate student in 1991 when a volcano erupted in the Philippines, sending a cloud of ash toward the edge of space.
Seventeen million tons of sulfur dioxide released from Mount Pinatubo spread across the stratosphere, reflecting some of the sun’s energy away from Earth.
The result was a drop in average temperatures in the Northern Hemisphere by roughly one degree Fahrenheit in the year that followed.
Global temperatures have hit record highs for 13 months in a row, unleashing violent weather, deadly heat waves and raising sea levels.
The main driver of the warming, the burning of fossil fuels, continues more or less unabated.
Persons:
David Keith, Keith
Locations:
Philippines, Mount Pinatubo, Northern