Paleoclimate Modeling, Pre-quaternary

Introduction Pre-Quaternary paleoclimate modeling is the science of simulating climate change over the earliest 99.9% of Earth’s history using numerical models of the climate system. The record of pre-Quaternary climate documents enormous climate swings with global ice-covered and ice-free end members. A number of climate factors shaped Quaternary and pre-Quaternary paleoclimate on timescales ranging from hundreds of thousands to several years. However, in contrast to Quaternary paleoclimate, tectonically-controlled processes (including continental drift, orogenies, and fluctuations in the long-term carbon cycle) and solar evolution were also important controls on pre-Quaternary climate. Understanding how these factors have influenced climate change through the Precambrian, Paleozoic, Mesozoic, and Cenozoic eras, and how they are expressed in the geological record is a principal objective of pre-Quaternary paleoclimate modeling. The utility of pre-Quaternary paleoclimate modeling has been severalfold. Pre-Quaternary climate modeling has contributed to ocean, atmosphere, and geological sciences by: (a) identifying mechanisms of climate change; (b) quantifying the climate response to a variety of forcing factors; (c) recognizing climatic feedbacks that amplify /dampen climatic forcings; (d) identifying limitations of climate proxies from the geological record; and (e) demonstrating strengths / shortcomings in numerical climate models. Pre-Quaternary paleoclimate modeling has made fundamental contributions to climate science. Among these, the recognition that the Earth’s climate has experienced enormous variability on a multitude of temporal and spatial scales as a result of complex interactions between multiple climate factors is one of the most profound.