HARD TIMES AT MONTICELLO - Tambora: The Eruption that Changed the World - page 124

the sun and winds, than the effects of cultivation begin to appear. The surface of the earth
becomes more warm and dry. As the settlements increase, these effects become more general
and extensive: the cold decreases, the earth and air become more warm; and the whole tem-
perature of the climate becomes more equal, uniform, and moderate … a remarkable change
of this kind has been observed in all the settled parts of North America. 29
Williams's arguments are not for marginal changes in weather but for wholesale transformation
of the American climate regime brought about by European settlement. He estimates that ag-
riculture has already warmed the inhabited parts of the country by 10°F (!) and that the be-
nign, seaborne easterly winds, which formerly intruded no more than “thirty or forty miles,”
were now blowing merrily hundreds of miles inland to the slopes of the Appalachian Moun-
tains.
In reading excited statements such as these—from the most respected scientific figures of
the early republic—it seems impossible to overstate the giddy rush of climate optimism felt
by educated Americans in the first decade of the nineteenth century. It was not to last. Iron-
ically, a new, enlarged edition of Williams's History of Vermont appeared in 1809—the year
the “Great Unknown” tropical eruption would usher in the coldest decade since European
settlement. Temperature readings in New Haven, Connecticut, showed the years 1812-18 to
be consistently 3-4°F below average. 30 Through the 1810s, the full-throated promotion of a
warming climate by the American scientific elite met the chill reality of a national climate
deterioration in which year after year posted a decline in average daytime temperatures and
a sharp uptick in extreme weather events.
The impact of the volcanic decade of the 1810s was felt most keenly in New England. Wil-
liams's beloved Vermont, for example, suffered a dramatic population decline from which it
did not recover for generations. This decade-long era of climate insecurity reached a chaotic
climax in the Tamboran summer of 1816. Faced by that demoralizing natural disaster, the
voices of the nationalist climate boosters fell conspicuously silent, while legions of ordinary
folk sold up and went West—the first American climate change refugees. As one Connectic-
ut resident remembered the crisis of 1816, “thousands feared or felt that New England was
destined, henceforth, to become a part of the frigid zone.” 31 The Buffonian nightmare was
coming true.
TAMBORA AND THE PANIC OF 1819
For all the trauma of 1816's extreme weather, however, the twin pillars of Jefferson's world-
view emerged from that meteorological disaster essentially intact. First, his climate optimism
stood vindicated by the fact of the weather emergency's being temporary, however drastic.
Normal temperature and precipitation patterns had resumed by the decade's end. Second, the
salvific potential of the West shone brightly through the crisis. The frontier west of the Ap-
palachians—“another Canaan” in Jefferson's eyes—was largely spared the monster cold fronts
that repeatedly swept down from Canada across the Atlantic seaboard in the summer months
of 1816. 32 Tree-ring studies that show “marked cooling” over western Europe and the eastern
United States in 1816 and 1817 indicate no such arboreal stress in the West. 33 Such is the
mix of cards dealt by climate change: the frontier, for the time being at least, profited wildly
from the transatlantic subsistence crisis. Farming territories from the Ohio Valley to Illinois