Chapter 5 explores the question: how do we read the clues about past climates in the sedimentary record? This exploration begins by describing where and how sedimentary rocks can be accessed for paleoclimate studies, and emphasizing the need to use sedimentary rocks and their proxies to examine Earth’s older climate record. Paleoclimate information can be interpreted from a wide variety of sediment characteristics, such as: physical and chemical characteristics of land-derived and inorganic chemical sediments; species assemblages and composition of biologically produced sediments; and detailed chemical and taxonomic characteristics of fossils. Each paleoclimate proxy has its own strengths and weaknesses, so the most scientifically robust interpretations are based on synthesizing data from multiple proxies. Constructing each accurate and detailed paleoclimate history requires combining the proxy paleoclimate data with accurate and detailed age determinations of the sediments containing those proxies.