Answer:
Paleoclimatologists use a variety of methods from Earth and life sciences to obtain data previously preserved within rocks, sediments, boreholes, ice sheets, tree rings, corals, shells, and microfossils. Combined with techniques to date the proxies, these paleoclimate records are used to determine the past states of Earth's atmosphere.
Explanation: The study of ancient climates helps us understanding how the climate system works--and how it might change in the future. Geologic records going back millions of years show that natural patterns, like shifts in Earth's orbit, can steer dramatic changes.
