The Asian Volcano that Forested New England

From Nature Wars: The Incredible Story of How Wildlife Comeback Turned Backyards into Battlegrounds by Jim Sterba:

There were lots of reasons to quit farming in New England in the nineteenth century, but one early event stands out: the most violent explosion in recorded history halfway around the world.

On the island of Sumbawa in the Dutch East Indies (now Indonesia) near the equator, a volcano named Tambora began to rumble and cough on the evening of April 5, 1815. On April 11 and 12, eruptions shook houses and boats hundreds of miles away. Over ten days, Tambora belched twenty-four cubic miles of lava and pulverized rock (try to imagine a cubic mile of anything), and created a crater more than three miles wide and nearly a mile deep. Flowing lava, flying rocks, and deadly gases killed thousands of people on Sumbawa and nearby islands. Earthquakes and tsunamis killed tens of thousands more. Hundreds of millions of tons of ash filled the sky, turning days into nights and blanketing the nearby island of Bali in a foot of volcanic soot. The ash smothered vegetation on islands for hundreds of miles around, and carpets of floating pumice covered the seas. An estimated 117,000 people in the region eventually died, many from starvation caused by crop failures and epidemics.

Tambora was much bigger (24 cubic miles of ejected debris) than Krakatoa (3.5 to 11 cubic miles), or the famed eruptions of Vesuvius (1.4 cubic miles) and Mount Saint Helens in Washington (less than 1 cubic mile).

The summer after the eruption — crop failures dotted the Northern Hemisphere. Rice failed in parts of China, wheat and corn in Europe, potatoes in Ireland (where it rained nonstop for eight weeks and triggered a typhus epidemic that killed sixty-five thousand and spread to England and Europe). Famine spread across Europe and Asia. Food riots and insurrections swept France, which had already been caught up in chaos following Napoleon’s 1815 defeat at Waterloo.

In New England, 1816 was called “the year without a summer” because there were crop-killing frosts every month, including normally frostfree months of summer, across the region. It snowed in Virginia in June and again on the Fourth of July. At Monticello, Thomas Jefferson, the retired president, had such a poor corn harvest that he had to borrow $1,000 to make up for lost income.

In their elegant 1983 book, Volcano Weather: The Story of 1816, the Year without a Summer, Woods Hole oceanographer Henry Stommel and his wife, Elizabeth, wrote: “The summer of 1816 marked the point at which many New England farmers who had weighed the advantages of going west made up their minds to do so.”

By 1840, reforestation was clearly evident in parts of New England. In western Massachusetts, perhaps half the farmland was abandoned within twenty years after 1850, and much of it was colonized by native white pines.