Measurements
from tree rings
identified the 1690s
as Scotland’s
coldest decade
in the past
750 years.
Historical records
from the same period
provided anecdotes
of crop failures and
famines causing deaths.
The unusual cold
affected much of the
Northern Hemisphere.
Scotland suffered
disproportionately,
and lost 10% to 15%
of its entire population.
“Scotland was
a miserable place
at that time,”
said Robert Wilson,
an Earth and
environmental
sciences professor
at the University of
St Andrews
in Scotland,
and senior author
on the study.
“We can speculate
that perhaps the fact
that Scotland was all alone
in terms of being a country
was one of the reasons
why their conditions
were much more vulnerable,”
said Rosanne D’Arrigo,
lead researcher
on the study and
associate director
of the Division of
Biology and Paleo
Environment at the
Lamont-Doherty
Earth Observatory
of Columbia University
in Palisades, N.Y.
Following the crisis,
Scotland entered into
Acts of Union
with England,
a political partnership
that allowed Scotland
to avoid suffering
further famine-related
catastrophes during
future cold periods.
The study was
recently published
in the Journal of
Volcanology and
Geothermal
Research,
shows interactions
between
climate change
and Scotland’s
economic and
political history.
Every August,
for the
past 10 years,
Robert Wilson
and his team
hunted for trees
at the bottom
of Scottish lakes.
Ancient wood,
buried in
lake sediment,
is preserved
well enough
to provide
clues to the
region’s climate
in past years.
The growth
of new tree rings
is well correlated
with the summer
temperature,
( summer is the trees’
growing season),
Wilson said.
If temperatures
are warm, the rings
are generally wider
and denser; in colder
temperatures,
the opposite
is true.
Climate
researchers
use tree ring
measurements
to extract
a climate signal
for each summer
a tree was alive
and growing.
Dendrochronology
is the use of tree ring
measurements
to date and interpret
past events.
Piecing together
samples from
long-dead remnant
( sub-fossil )
trees in lakes ,
with other samples
nondestructively
collected from
living trees
(typically
only a
few hundred
years old),
researchers
reconstructed
a temperature
timeline
for Scotland.
Patrick Klinger,
a historian from the
University of Kansas,
helped uncover
historical documents
that corroborated
the tree ring data,
a process that
he said was
“more often
than not,
stumbling upon
[ the documents ]
in the archives.”
Patrick Klinger
noticed that
in the 1690s,
people started
recording more
and more
cold climate
conditions
in Scotland.
“Especially
by 1698,
it’s amazing
how many
more records
you have
during that year
talking about
the conditions
and basically
how awful and
how different
they are,”
he said.
The bad
climate
conditions
of the 1690s
helped motivate
a daring scheme
to improve Scotland’s
economic standing
by colonizing
the Darién region
in what is now Panama.
But disease, famine,
mismanagement, and
Spanish attacks,
hit the Scottish
colonists in Panama,
and the
Darien Scheme
collapsed.
“Between 15%,
to upwards
of about 40%,
of all the actual
capital in Scotland
was invested
in this project,”
said Patrick Klinger.
The colony’s failure
left Scotland in
an even worse
economic situation,
and helped trigger
the Acts of Union
with England.
“This is a nice piece of
interdisciplinary work
on a regional scale
linking historical
evidence with
paleoclimate
natural information,”
said Jürg Luterbacher,
director of the Science
and Innovation
Department at the
World Meteorological
Organization.