Contents - Winter 2009
Vol. 2 No. 1
The Indiana Jones of Climate Change Research
Gathering research data from
across North America, Bill
Patterson made BMW’s 2008
Top Five list for most miles
ridden on a motorcycle.
By Brian Cross
Bill Patterson has gone cave
diving, waded through
crocodile-infested swamps,
and trekked across the
seven continents—all in a
quest to better understand
global climate and
environmental changes.
Bill Patterson’s travel log would make Indiana
Jones, the swashbuckling fictional adventurer,
green with envy.
The University of Saskatchewan geologist has
gone cave diving, waded through crocodile-infested
swamps, and trekked across the seven continents—
all in a quest to better understand global climate and
environmental changes.
To recreate an accurate historical record of global
climate patterns, Patterson, his graduate students,
and colleagues have visited more than 80 different
countries, collecting and studying a variety of
unusual materials.
They’ve examined bat droppings taken from
caves in Mexico and Arizona, tree-ring samples
gathered on South Pacific and Arctic islands,
sediment samples found on remote lake bottoms in
Central America, and clam shells collected along the
shores of Iceland.
And last summer, Patterson strapped 350 bottles
on the back of his motorbike and travelled 26,000
kilometres to collect samples in the Prairies, New
York, Northwest Territories, Yukon, Alaska and
British Columbia.
The jaunt earned him a place on BMW’s 2008
top five list for most miles ridden on a motorcycle,
but bragging rights weren’t the motivation for his
endurance ride or any of his other sample-collecting
adventures.
“What we’re trying to do is get a handle on how
the world works through biology, geology, climate
change research, or oceanography—everything that
we can find the time and funding to investigate,”
Patterson said. “The only way to do that is to develop
good quality, high-resolution records of the past.”
He thinks his research will add a new layer of
understanding to the ongoing debate surrounding
the role of human activity in global climate change.
“We’re often surprised in this business,” said
Patterson. “We have an idea of what we think might
be happening but the data suggest something
else.”
A case in point is the Adelie penguin,
a bird species considered by many to be
a beacon of changing climates in the
Antarctic region.
Adelie penguin numbers are falling significantly in
the area and it has been widely assumed that there is a
direct correlation between climate change and the bird’s
diet.
But Patterson’s research produced some unexpected
findings that suggest climate change may not be the
culprit.
The researcher examined penguin feces and eggshell
fragments, using radiocarbon dating to determine age,
and stable isotope analyses to determine diet.
Patterson concluded that the penguin’s diet had
changed significantly over the last 10,000 years, with
nearly all of the change occurring during the 19th and
20th centuries.
In collaboration with University of North Carolina
researcher Steven Emslie, Patterson found that while
the recent disappearance of Antarctic sea ice might be
affecting the penguin’s ability to feed and reproduce,
there was another key variable at play that may have
affected its feeding habits and its environment.
“The thing we came up with was the effect of
whaling and sealing operations,” Patterson said.
According to the research team, changes in the
penguin’s diet became evident in the 1800s, when
commercial whaling operations began to have a
significant impact on the Antarctic ecosystem.
Whales and seals feed primarily on krill, a
small shrimp-like animal that thrives in the area.
As whaling and sealing operations increased,
predation pressures decreased and krill numbers
exploded, providing an abundant alternative food
source for the penguins—which had been feeding
primarily on fish and squid.
This phenomenon, known as the “excess krill
hypothesis,” may have changed the ecosystem
significantly.
“Suddenly there was this enormous supply of
very nutritious food available and the penguins,
who were being chased by orcas and leopard seals,
saw an opportunity to get a quick shrimp cocktail
and get out of the water before they were eaten
themselves,” Patterson said.
“There was an obvious advantage for the
penguins to change their diets, so that’s what they
did.”
The case of the Adelie penguin shows how disruption
of a complex ecosystem can have an unexpected and
long-lasting impact.
For example, had the penguin continued to feed on
fish rather than krill, it might have been better equipped
to cope with the loss of Antarctic sea ice.
Another of Patterson’s projects, funded by the Natural
Science and Engineering Research Council and the U.S.
National Science Foundation, examined growth rings
on tiny mollusk shells collected in Iceland. Analysis of
the shells helped to recreate a climate record for Iceland
and Greenland between 360 BC and 1850 AD.
The findings support the theory that minor variations
in annual temperatures in the North Atlantic had a
significant negative impact on the ability of ancient
Norse cultures to grow crops and survive.
As for our current understanding of global
climate change, it is extremely difficult to gauge
the impact of human activity relative to other
factors such as changing ocean currents, solar
variability, changes in atmospheric chemistry
and increases in the natural production of
water vapours, Patterson said.
“In all reality, you could go on for weeks
and weeks discussing all of the complexities
of the climate system and what we
don’t understand,” he said, adding, “It’s
getting warmer and greenhouse gases are
increasing, but how are the two related? We
just don’t know yet.”
“The things we know for sure are that climate
has always changed in the past, it’s changing now,
and it’s going to change in the future. People have
likely only had some influence over the last 5,000 to
8,000 years.”
