Introduction: Hydrogen isotopes as environmental recorders

International audienceInterpreting past environmental conditions is often a prerequisite for advancing research in areas as fundamental and diverse as the evolution of life and the consequences of climatic change for the future of societies. Stable hydrogen isotopic ratio (D/H) analyses of organic compounds preserved in natural archives such as soils and sediments, are finding increasing applications for revealing past hydrological conditions (Eglinton and Eglinton, 2008; Sachse et al., 2012). At the crux of these applications is a physical relationship between the D/H of meteoric water and climate caused by the effects of temperature and availability of cloud water on the precise distribution of isotopes in precipitation (Dansgaard, 1964; Yurtsever, 1975; Gat, 1980; Vimeux et al., 1999). The D/H of organic compounds contains information about climate because the original source of hydrogen in any organic compound can ultimately be traced to precipitation (Estep and Hoering, 1980; Estep and Dabrowski 1980; Sternberg, 1989)