Answer:
The June 1991 eruption of Mount Pinatubo was global.
Slightly cooler than usual temperatures recorded worldwide and
the brilliant sunsets and sunrises have been attributed to this
eruption that sent fine ash and gases high into the
stratosphere, forming a large volcanic cloud that drifted around
the world. The sulfur dioxide (SO2) in this cloud -- about 22
million tons -- combined with water to form droplets of sulfuric
acid, blocking some of the sunlight from reaching the Earth and
thereby cooling temperatures in some regions by as much as 0.5
degrees C. An eruption the size of Mount Pinatubo could affect
the weather for a few years.
A similar phenomenon occurred in April of 1815 with the
cataclysmic eruption of Tambora Volcano in Indonesia, the most
powerful eruption in recorded history.
Tambora's volcanic cloud lowered global temperatures by as much
as 3 degrees C. Even a year after the eruption, most of the
northern hemisphere experienced sharply cooler temperatures
during the summer months. In parts of Europe and in North
America, 1816 was known as "the year without a summe.
