News Tip: New Disaster Flick
Gets Mechanism of Global Warming Right, but Its
Timing is All Wrong
Film miscalculates the time it would take for
an ‘Instant Ice Age’ to occur by as much as a
century, says a Duke oceanographer who studies
ocean currents and climate change: “It’s like
saying someone can run a mile in less than a second.”
Friday, May 7, 2004 – The cataclysmic ice age
scenario depicted in the upcoming movie, “The
Day After Tomorrow,” gets the mechanics of global
warming mostly right, but wildly exaggerates the
speed at which it might occur, says Susan
Lozier, a Duke University oceanographer
who studies North Atlantic ocean currents.
“Hollywood time is not, obviously, the same as
geological time,” Lozier said. The type of global
climate change that happens in the movie – where
global warming diverts warm ocean currents and
plunges the world abruptly into a new ice age
– could possibly happen in real life, she said,
“but it would take many, many decades or even
a century or more.”
Lozier is the Truman and Nellie Semans/Alex Brown
& Sons Associate Professor of Earth and Oceans
Sciences at Duke’s Nicholas School of the Environment
and Earth Sciences.
She is a principal investigator in a five-year,
National Science Foundation-funded study of the
circulation pathways of North Atlantic currents,
and has published findings from her work in Science,
the Journal of Physical Oceanography and other
leading journals.
Despite its inaccuracies, Lozier believes “The
Day After Tomorrow,” which is slated to open May
28, may prove beneficial to the policy debate
about global warming by raising public awareness
of the oceans’ role in climate and climate change.
“When people think about global warming, they
think about the whole world getting warmer due
to greenhouse gases. They may not realize that
some parts will get warmer and some will get colder,
some will get wetter and some will get drier,
due in part to changes in ocean currents,” Lozier
said.
The oceans, she explains, store a tremendous
amount of heat from the sun, and their currents
act like a giant conveyor belt, redistributing
that heat around the globe. The Gulf Stream, for
example, carries tropical warmth far into the
North Atlantic, giving western Europe a mild,
moist climate despite its northerly latitude.
Current paths are driven by the prevailing winds
and density differences that exist between cold
and warm water, and salty and fresh water. Alter
any of these factors, Lozier says, and a current’s
path will change, altering over time the climate
of lands in or near its path.
Her research – including a paper in the January
2004 issue of Geophysical Research Letters that
documents the warming and salinification of Mediterranean
waters – has identified subtle changes taking
place in North Atlantic waters over the past 50
years. Waters at high latitudes, such as in the
subpolar regions, are becoming colder, less salty
and slightly less dense, while waters at low latitudes,
such as those nearer the equator, are growing
warmer, saltier and slightly denser.
“If this continues, it could, in theory, disrupt
the circulation of North Atlantic currents and
cause them to slow or eventually shut down,” Lozier
said. “Earth goes in and out of ice ages, and
this is a process that continues today. Only it
doesn’t happen anywhere nearly as suddenly as
it does in the movie. That’s pretty far-fetched.
It’s like saying someone can run the mile in less
than a second.”
For more information, contact Susan Lozier at
(919) 681-8199 or s.lozier@duke.edu,
or Tim Lucas at (919) 613-8084 or tdlucas@duke.edu. |
