Ancient records help test climate change

Here's some interesting historical excepts from early weather diaries

the greens and not so greens will still not completely agree on, but

at least boths camps should gain a least a little insight from it.

Ancient records help test climate change By BRADLEY S. KLAPPER,

Associated Press Writer

Sat Sep 15, 10:50 AM ET

EINSIEDELN, Switzerland - A librarian at this 10th century monastery

leads a visitor beneath the vaulted ceilings of the archive past the

skulls of two former abbots. He pushes aside medieval ledgers of

indulgences and absolutions, pulls out one of 13 bound diaries

inscribed from 1671 to 1704 and starts to read about the weather.

"Jan. 11 was so frightfully cold that all of the communion wine

froze," says an entry from 1684 by Brother Josef Dietrich, governor

and "weatherman" of the once-powerful Einsiedeln Monastery. "Since

I've been an ordained priest, the sacrament has never frozen in the

chalice."

"But on Jan. 13 it got even worse and one could say it has never been

so cold in human memory," he adds.

Diaries of day-to-day weather details from the age before 19th-century

standardized thermometers are proving of great value to scientists who

study today's climate. Historical accounts were once largely ignored,

as they were thought to be fraught with inaccuracy or were simply

inaccessible or illegible. But the booming interest in climate change

has transformed the study of ancient weather records from what was

once a "wallflower science," says Christian Pfister, a climate

historian at the University of Bern.

The accounts dispel any lingering doubts that the Earth is heating up

more dramatically than ever before, he says. Last winter - when spring

blossoms popped up all over the Austrian Alps, Geneva's official

chestnut tree sprouted leaves and flowers, and Swedes were still

picking mushrooms well into December - was Europe's warmest in 500

years, Pfister says. It came after the hottest autumn in a millennium

and was followed by one of the balmiest Aprils on record.

"In the last year there was a series of extremely exceptional

weather," he says. "The probability of this is very low."

The records also provide a context for judging shifts in the weather.

Brother Konrad Hinder, the current weatherman at Einsiedeln and an

avid reader of Dietrich's diaries, says his predecessor's precise

accounts of everything from yellow fog to avalanches provide

historical context.

"We know from Josef Dietrich that the extremes were very big during

his time. There were very cold winters and very mild winters, very wet

summers and very dry summers," he says, adding that the range of

weather extremes has been smaller in the 40 years he has recorded data

for the Swiss national weather service.

"That's why I'm always cautious when people say the weather extremes

now are at their greatest. Without historical context you lose control

and you rush to proclaim every latest weather phenomenon as extreme or

unprecedented," Hinder says.

Most historians and scientists delving deep into archives seek

accounts of disasters and extreme weather events. But the records can

also be used to obtain a more precise temperature range for most

months and years that goes beyond such general indicators as tree

rings, corals, ice cores or glaciers.

Such weather sources include the thrice-daily temperature and pressure

measurements by 17th-century Paris physician Louis Morin, a short-

lived international meteorological network created by the Grand Duke

of Tuscany in 1653, and 33 "weather diaries" surviving from the 16th

century. In Japan, court officers kept records of the dates of cherry

blossom festivals, which allow modern scientists to track the weather

of the time.

Early records often are only discovered by chance in documents that

have survived in centuries-old European monasteries like Einsiedeln,

or in the annals of rulers, military campaigns, famines, natural

hazards and meteorological anomalies. In Klosterneuberg near Vienna an

unidentified writer notes a lack of ice on the Danube in 1343-1344 and

calls the winter "mild," while the abbot of Switzerland's Fischingen

Monastery laments the late harvest of hay and corn in the summer of

1639 when "there was hardly ever a really warm day."

Scores of similar clues are pieced together year by year to determine

temperature ranges, says Pfister, whose team of four uses old "weather

reports" to work back as far as the 10th century.

Pfister has found that from 1900 to 1990, there was an average of five

months of extreme warmth per decade. In the 1990s, that number jumped

to an unprecedented 22 months. The same decade also had no months of

extreme cold, in contrast to the half-millennium before.

Even in the last major global warming period from 900 to 1300, severe

winters were only "somewhat less frequent and less extreme," Pfister

says. Over the past century, temperatures have gone up an average of

1.3 degrees Fahrenheit, which is often attributed to the accumulation

of greenhouse gases, primarily carbon dioxide, in the atmosphere.

Global warming is one of the world's top issues today because of fears

of massive hurricanes and flooding. For most of history, though, it

was the fate of farms and the fear of famine that encouraged careful

weather observation.

The Einsiedeln abbots - princes within the Holy Roman Empire until

1798 - were powerful leaders who ruled over large swaths of central

Switzerland's mountainous terrain. Agriculture was the primary source

of income for the region and natural disasters such as floods and

avalanches posed an omnipresent threat.

Debts accrued and honored, accidents, local conflicts and business

transactions also fill Dietrich's accounts, "but most days start with

the weather," says Andreas Meyerhans, who cares for the monastery's

precious documents.

The diaries - written in German sprinkled with old Swiss dialect and

margin notes in Latin - are "unique" because of the exceptional

everyday detail they provide, Pfister says. He adds that centuries of

weather records make it clear that people need to adapt when extremely

hot or cold weather becomes more frequent. While the lives of earlier

generations were ruled by the weather, "in the second half of the 20th

century people slept and became completely unprepared for natural

disasters, because they happened so rarely."

In Einsiedeln, Hinder reads from a barometer flanked by the Virgin

Mary, and worries that humanity is in trouble.

"God still controls the weather," he says. But, he adds, people must

do their part by taking better care of the planet.