What
is
climate
____________________
?
The
planet's
____________________
has
constantly
been
changing
over
geological
time
.
The
global
average
____________________
today
is
about
15C
,
though
geological
evidence
suggests
it
has
been
much
higher
and
lower
in
the
past
.
However
,
the
current
period
of
____________________
is
occurring
more
____________________
than
many
past
events
.
____________________
are
concerned
that
the
natural
fluctuation
,
or
variability
,
is
being
overtaken
by
a
rapid
____________________
-
induced
warming
that
has
serious
____________________
for
the
stability
of
the
____________________
climate
.
