Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of oxygen-18 and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm interglacial intervals. Marine isotope stages ( MIS), marine oxygen-isotope stages, or oxygen isotope stages ( OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data derived from deep sea core samples. Alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data 5-million-year history, representing the Lisiecki and Raymo (2005) LR04 Benthic Stack Sections of sedimentary cores from off Greenland
