the explorers journal the climate change issue - The Explorers Club

exploring climate change No. 1
Venturing
Of the
to the Ends
Earth
exploring our planet’s polar regions:
chroniclers of the past and portents of the future
by Paul Andrew Mayewski
It has been 50 years since the first International
Geophysical Year (IGY) invited the best minds in
science from around the globe to join forces in tackling
issues such as understanding Earth’s oceans
and atmosphere and the delicate relationship
between them. Since then, many advances have
been made in this area, among the most important,
the understanding of the role of greenhouse
gases such as carbon dioxide (CO 2
) in determining
Earth’s climate. In more recent years, a realization
that gases such as CO 2
are on the rise has led to an
interest in determining and documenting past levels
of greenhouse gases. Gathering such information,
however, entails journeying literally to the ends of
the Earth. For there, locked in thousands of meters
of ice, are records of our planet’s changing chemical
and physical climate that stretch back nearly a
million years.
When I began my climate research nearly 40
years ago, few in the scientific community regarded
Earth’s polar regions as important to the
vast majority of civilization. At that time, Antarctica
was viewed as not only a frozen continent but also
a continent frozen in time. This view seemed to
be amply supported by the ice-free valleys of the
Victoria Land Coast in East Antarctica, where
rocks had been exposed to millions of years of
wind erosion, creating timeless landscapes. The
vast interior of the polar plateau also appeared to
be changeless to the few limited expeditions that
passed but once across the surface.
Increased access to the most remote portions
of Antarctica and the Arctic—afforded by aircraft
and ship in recent years—complemented by our
ability to mount lighter, faster, and more efficient
expeditions and establish well-equipped field stations,
has resulted in the acquisition of an abundance
of information that is dramatically changing
our understanding of the critical role polar regions
play in Earth’s complex ecosystem.
Remarkably, these regions have now emerged
as “first responders” for monitoring current climate
because they are so sensitive to warming;
the vast ice-trapped environmental libraries they
host chronicle hundreds of thousands of years of
Earth’s climate history. The ice cores we extract
from the polar regions contain highly robust records
of past climate. These ancient records not
only allow us to better understand the long-term
cyclical changes in climate caused by natural phenomena
such as the 26,000-year precession of
the equinoxes, which is in part responsible for the
ice ages; volcanic eruptions; and solar activity, but
to separate these factors from variations in climate
22 the explorers journal