&
BY OUR EXPERT PANEL
YOUR QUESTI0NS ANSWERED
DR
CHRISTIAN
JARRETT
Christian is a
psychology and
neuroscience
writer. His latest
book is Great
Myths Of
The Brain.DR
ALASTAIR
GUNN
Alastair is an
astronomer
at the Jodrell
Bank Centre for
Astrophysics at
the University of
Manchester.PROF
ROBERT
MATTHEWS
Robert is a
physicist and
science writer.
He’s visiting
professor in
science at Aston
University.LUIS
VILLAZON
Luis has
a BSc in
computing
and an MSc in
zoology. He is
author of How
Cows Reach
The Ground.DR PETER
J BENTLEY
Peter is a
computer
scientist and
author who
is based at
University
College
London. His
latest book is
Digitized.The Earth’s axis isn’t perfectly
upright relative to its orbit, but
instead is tilted at an angle of around
23.5°. This so-called obliquity has
long been known to change slightly
over thousands of years as a result
of the gravitational influence of
the Sun, the Moon and the other
planets. But evidence is also
emerging for effects resulting from
climate change. In 2013, researchers
at the University of Texas reported
that satellite measurements had
revealed that the Earth’s tilt is being
affected by the shift in mass caused
by the melting of ice covering
Greenland. The team found that
around 15 years ago the Earth’saxis began to move east and then
south. Earlier this year, researchers
at NASA’s Jet Propulsion Laboratory
confirmed the effect, and added
another cause: changes in the
amount of water stored in the Earth’s
continents. Lower rainfall over
Europe and Asia in recent years
seems to be adding to the axial drift.
So is man-made global warming
to blame for these changes?
According to the JPL team, it’s
probably just part of the Earth’s
natural climatic rhythms.
Either way, the effect isn’t anything
to lose sleep over: the recent shift
amounts to less than one-millionth
of the Earth’s total tilt angle. RMCould global
ice melt affect
the Earth’s tilt?
Strong winds and frosts
caused ice to crack on
PHOTO: ALEXEY TROFLMOV/SOLENT NEWS Siberia’s Lake Baikal