摘要：The last few hundred thousand
years form the context in which
we can learn how the Earth System
(including its climate) works.
Although the geological setting
of the Earth was similar to today,
very signifi cant changes occurred
in the climate, the circulation of
the ocean, and the composition of
the atmosphere. By learning about
these changes, we can understand
the processes that can occur, and
that should be represented by models—
the same models that will be
used to predict future conditions.
