Every American schoolchild learns a version of the first Thanksgiving, a story half-legend and half-history: After the Pilgrims spent a freezing first winter in Plymouth, friendly Native Americans helped them learn to harvest the bounty of their new country the next year. As the Pilgrim Edward Winslow wrote in a letter late that autumn of 1621, "Many of the Indians coming amongst us . . . we entertained and feasted."
The story gets more interesting when we look at the first mention of an actual "thanksgiving" at Plymouth. Less than two years after that 1621 feast, the colony faced drought and famine. In his personal history of the colony, Pilgrim William Bradford described how the English declared a day of repentance and prayer. Then God sent them a sudden rain "both to their own and the Indians' admiration . . . for which mercy, in time convenient they also set apart a day of thanksgiving."
We could write this off as just a curious anecdote, if it weren't for a dozen other accounts of similar episodes in other early colonies. By the time the Pilgrims came to New England, Europeans had been trying to settle North America for more than a century. The first Spanish expeditions to the South and Southwest produced tales much like Bradford's, as did colonists in the Carolinas and Virginia, and missionaries in Spanish Florida and French Canada. In many cases, they reported Indians asking them to pray for better weather — to intercede with that Christian God they talked so much about, if the Indians' gods weren't up to the task.
We should take their stories with a grain of salt. But there is other evidence that something unusual was going on during many of these early encounters. Advances in paleoclimatology, the science of reconstructing past climates from records such as tree rings and lake sediments, show how America in the late 1500s and early 1600s was getting cooler and more prone to drought. The trend was part of a global pattern sometimes called the Little Ice Age. The causes were complex, but the effects were unmistakable — and the way the Pilgrims coped (and failed to cope) with the shock of a new and harsh climate can serve as a warning to us as we face a rapidly changing environment.
Narrow growth rings in nearby stands of trees indicate that each story of supposedly miraculous rain prayers really did take place during a drought. Many European expeditions happened to arrive during exceptionally bad years of frozen winters and parched summers. Between 1540 and 1541, for example, followers of Hernando de Soto reported snow storms in Arkansas and Alabama, and followers of Coronado rode horses over the frozen Rio Grande; the first Spanish explorers in California found the mountains of Monterrey Bay covered in snow, and the first English colonies at Roanoke and Jamestown starved during the region's worst droughts in centuries.
For early explorers and colonists, the Little Ice Age was only half the problem. The English, French and Spanish experienced climate shock in another sense when they crossed the Atlantic. Prevailing westerly winds at mid-latitudes mean that air passes over the ocean into Europe, producing a milder maritime climate compared with the variable seasons of North America, where air passes over the continental interior. Europeans of the era imagined that climates would be more or less the same along the same latitudes — meaning Virginia would have the seasons of Sicily, and New England those of southern France. Colonists thus tried and failed to cultivate tropical fruits in Virginia and silkworms in Maine. It took decades of disasters for America's climate realities to sink in.
By Little Ice Age standards, the Pilgrims' first winter at Plymouth wasn't especially cold, and the drought of 1623 wasn't especially bad. But neither were their troubles over. A decade later, two years of severe drought followed by a destructive storm brought famine. Desperate to seize food and land, Massachusetts settlers launched a war against neighboring Pequot Indians in 1636, massacring hundreds of men, women and children in the region's worst colonial conflict.
Those early challenges that Pilgrims saw as providential tests of their faith now look like something more prosaic and familiar: The Pilgrims were simply unprepared for a shift in climate. They gave thanks — prematurely, it turned out — once it looked like the worst seasons had passed. But the colonists didn't really thrive until they themselves changed, by adapting to New England's climate and learning to raise crops and livestock in a way the region could support.
In this way, the Pilgrims have left us a more compelling story for a modern national holiday than the questionable tales of Anglo-Indian friendship that we teach our children — and one more relevant to the present day. In late November, we can look forward to the weather cooling down across America, and some of us — though probably not those in Houston or Puerto Rico — can perhaps begin to forget about the record heat waves, hurricanes and floods of the past months. Most of us can give thanks that we made it through another summer of climate shock relatively unscathed.
But the climate fluctuations of the Little Ice Age were only a fraction of the climate change projected under most global warming scenarios. We can't let the reprieve of fall and winter turn our attention away from the climate realities ahead and the need to adapt, even as we give thanks for gentler weather now.