THE LITTLE (VOLCANIC) ICE AGE - Tambora: The Eruption that Changed the World - page 19

stands as the most catastrophic sustained weather crisis of the millennium. The year follow-
ing Tambora, 1816, has long enjoyed the folkloric status of the “Year without a Summer.”
But this is faint praise (or blame), indeed. The celebrity of 1816, as a year apart, obscures
the greater climatological and social history of the 1810s, of which Tambora's eruption is the
explosive centerpiece. Nor should we view Tambora's global impact “merely” as an extreme
weather regime limited to the late 1810s. Just as the influence of volcanism on climate may
extend centuries, as in the case of the Little Ice Age, so the social changes wrought by climat-
ic upheaval on the scale of 1815-18 may be traced decades into the future, as the following
chapters will show.
Fast forward to the twentieth century, and we find only Alaska's Mount Katmai in 1912
and Mount Pinatubo in the Philippines in 1991 erupting on a scale so frequently reached dur-
ing the Little Ice Age. Even mighty Pinatubo, the century's largest volcanic event, rates an
order of magnitude smaller than Tambora, lower even than Tambora's little brother, the 1809
Unknown. 22 Living in New York as I was during the snowy winter of 1991-92, Pinatubo's grip
on global climate felt sharp enough! Just arrived from balmy southern Australia, battling the
snow and frigid wind in my wholly inadequate outerwear, I wondered how it had occurred
to anyone to establish a civilization in such an inhospitable place. In the Tambora year 1816,
many residents of New England and the Atlantic seaboard came to the same conclusion, with
profound consequences for the history of the United States (a story that must wait for chapter
9 ) .
SCALING TAMBORA
Tambora, in its decapitated state, stakes a serious claim as the most destructive volcano in hu-
man history. In light of this, the celebrity of Krakatau's more modest eruption in 1883 seems
undeserved. Only the historical accident of the telegraph's invention allowed news of it to
travel almost instantly across the globe. Perhaps now, with its bicentenary upon us, Tambora
will at last achieve a popular recognition equal to its vaunted reputation among scientists.
But how big was the Tambora event on a geological timescale? According to the Global
Volcanism Program at the Smithsonian Institution, the so-called Holocene Period—the ap-
proximately twelve thousand years since the last glacial epoch—marks the “official” time
frame of volcanic history. Not coincidentally, the consistent, more moderate temperatures
characteristic of the Holocene—which have not fluctuated more than a degree in warmth or
cold in those twelve millennia—have witnessed great leaps forward for the human race, from
a precarious existence in nomadic hunter bands, to literate settler farmer communities, to the
advanced technological mass societies of the twenty-first century—a planet literally teeming
with humanity.
According to the methodology employed by the Smithsonian—which measures magmatic
output deduced from geological sediments and historical accounts—Tambora belongs to an
elite group of some half-dozen Holocenic volcanoes that rate 7 on the Volcanic Explosivity
Index (VEI), a size officially termed “colossal.” 23 Volcanologists are quick to concede the lim-
itations of the index, which gets fuzzier the further back in time one goes. Many important
volcanoes are simply missing from the Smithsonian tables, including the great “Unknowns”
of 1258 and 1809. Furthermore, paleoclimatologists complain, the VEI measures explosive