1) Palaeoclimatology 
Paleoclimatology (in British spelling, palaeoclimatology) is the study of changes in climate taken on the scale of the entire history of Earth. It uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within (e.g.) rocks, sediments, ice sheets, tree rings, corals, shells and microfossils; it then uses...
scientific study of the climatic conditions of past geologic ages. Paleoclimatologists seek to explain climate variations for all parts of the Earth ... [21 related articles]
Paleoclimatology meaning study of ancient climates) is the study of the climates during ancient times. 
Scientific study of the Earth's climate during the past.
the study of climate change taken on the scale of the entire history of Earth.
[n] - the study of the climate of past ages
palaeoclimatology noun the study of the climate of past ages