I am an organic geochemist, applying rigorous state-of-the-art isotopic and organic mass spectrometry to molecular fossils (biomarkers) derived from organism across the three Domains of Life to answer long-standing questions related to the processes and mechanisms that drive changes in climate and biogeochemistry. The applications are broad, but in general fall into three themes: Cryosphere-land-ocean interactions during the Quaternary; global climate and biogeochemistry (C and N-cycles) during the Oceanic Anoxic Events of the Mesozoic; and at present I focus on terrestrial climate and biogeochemistry, bridging the modern and geological record as well as marine/terrestrial interface.