Patchwork of past reveals what humanity has weathered

It was “an old ring-tail snorter of a snowstorm,” wrote New Englander George Lang in his February 1893 diary – not exactly scientific precision, but a vivid statement nonetheless.

Descriptive climate observations can bring tallies of temperatures and rainfalls to life, but increasingly scientists are turning to historical accounts and archaeological digs to fill gaps in the climatological record.

Initially, scientists were hesitant to work alongside their counterparts in the humanities, and for historians, climate has rarely been considered a major factor. But over the past 20 years the two disciplines have converged.

Layers in ice cores can be precisely dated by tying a layer of volcanic dust to recorded human events, such as the eruption of Mount Vesuvius at Pompeii in A.D. 79.

Historic “instrument records” – the exact measurements of rainfall and snowfall – have survived from many cultures. European records were the first heralds of the Little Ice Age, which later was verified by ice core data. In China, centuries of observations are just now being analyzed by a growing community of climate experts. But precise measurements are limited.

“In the 1800s, there were just a couple of thermometers here and there,” said Kirk Maasch, an atmospheric scientist with the University of Maine Climate Change Institute.

In other cases, archaeological digs tell the tale. Dan Sandweiss studies climate change through the institute, but he has never taken an ice core, never visited a glacier. The University of Maine anthropologist studies climate change to understand ancient civilizations. His analysis of mollusk shells left behind in Peruvian settlements shed light on how the El Nino weather pattern functioned thousands of years ago and how it affected human societies.

About 5,000 years ago, at a time when El Nino was predictable, the culture flourished, building temples and expanding its population, Sandweiss said. But when the El Nino cycle changed around 2,500 years ago, bringing dramatic and unpredictable weather shifts every few years, temple building stopped as the culture waned, he said.

Elsewhere, researchers tap records of the wine harvest, fluctuations in grain prices and personal diaries to bring the scientific data about the Little Ice Age and El Nino to life.

For many years, faculty and students at the Climate Change Institute have collected these accounts into an internal library of climate change in New England.

They have data from the early weather station at Dartmouth College in New Hampshire and from climate-related entries from William Bradford’s diary, written at Plymouth Plantation in 1623.

About 300,000 items have been digitized so that researchers can search by location or date. But that’s just a fraction of the data that exist, untapped in the attics and basements of every small town, said state climatologist Greg Zielinski, one of the project’s organizers.

“You could do this for years,” he said.

To explore the database of New England climate records, visit www.umaine.edu/oldweather.