Scientists study small pockets of air trapped deep within frozen glaciers. what are scientists trying to understand about the climate of earth by analyzing these ice samples?

What scientists are trying to understand about the climate of earth by analyzing these ice samples is changes in atmospheric gas composition.

By examining small pockets of air trapped deep within frozen glaciers, these scientists want to see whether or not, or how gas composition within these glaciers changes and how it affects the atmosphere that surrounds our planet.