A Brief Overview of Some Molecular Proxies Commonly Used to Unravel Part of the Earth’s Climate History

Abstract

Molecular proxies, also named organic biomarkers, have increasingly been used over the last decades in both marine and continental environments to track past climate variability at several timescales. Marine and terrestrial living organisms synthetize organic compounds, in particular some lipids that are exported to lake and deep ocean sediments where they remain preserved for million years. Based on their distribution, abundances, and isotopic signatures, they can reveal crucial information on changes in ocean and atmosphere temperatures, marine phytoplankton productivity, sea ice extent, type of vegetation, or precipitations for instance. Here is presented a brief review of some marine and terrestrial organic proxies that have been commonly used to reconstruct past climate changes in both low, mid, and high latitudes regions during different periods of time.