The satellite record is only a little over 20 years old and the
instrumental record only extends back into the 19th century. Both of
these records can be too short to study certain climate processes that
occur over hundreds to thousands of years.
instrumental record only extends back into the 19th century. Both of
these records can be too short to study certain climate processes that
occur over hundreds to thousands of years.
To extend those records, paleoclimatologists look for clues in
Earth’s natural environmental records. Clues about the past climate are
buried in sediments at the bottom of the oceans, locked away in coral reefs, frozen in glaciers and ice caps,
and preserved in the rings of trees. Each of these natural recorders
provides scientists with information about temperature, precipitation,
and more. Many of these have some type of layers, bands, or rings that
represent a fixed amount of time, often a year or growing season. The
layers vary in thickness, color, chemical composition, and more, which
allows scientists to extrapolate information about the climate at the
time each layer formed.