Paleoclimatology or more generally paleo-science is the study of weather and its environmental change before records of such took place. The instrumental records as they are called consist of precipitation or temperature and have been available for the past 100 years. Climate throughout Earth's history has left and continuous to leave chemical and physical structural imprints of its effect on the oceans, life, and land. It is clear that the instrumental data already known cannot allow for such long-term understanding, thus other tools are needed. Through paleoclimatic, paleoceanographic, and paleoecologic records understanding is achieved to determine variations of weather over not merely decades but millennium if needed.
So-called proxy data such as tree-ring dating, skeletons of tropical coral reefs, ice cores from glaciers as well as ice caps, and buried sediments from lakes and oceans are taken by evolutionists in some cases to represent millions of years past time. These sets of data reveal general climate patterns which can be put into computer models to aid in the prediction of future climate changes. The word, "paleo" means involvement or dealings with ancient forms or conditions . It is used to gain a paleo-understanding of weather data from as far back as possible. 
- Main Article: Global warming
The term global warming is used to define periods of continual warming of Earth's climate. It is derived from paleoclimatology data, computer climate models and other data sets that reveal average temperatures of the atmosphere and oceans.
- Paleo Merriam-Webster
- Paleoclimatology and climate system U.S. National Report to IUGG, 1991-1994. Rev. Geophys. Vol. 33 Suppl., © 1995 American Geophysical Union.
- Paleoclimatology Earth Observatory
- Paleoclimatology and climate system dynamics by Jonathan T. Overpeck. NOAA Paleoclimatology Program, Boulder, Colorado.
- Climatology and Paleoclimatology Resources S. Baum. Dept. of Oceanography, Texas A&M University.