Can you look back into the past using algae skeletons? The researchers from the isotope lab at the Alfred Wegener Institute in Potsdam will soon make it possible, by oxygen isotope analysis of silica-secreting algae. The skeletons of the silica-secreting algae, the diatomea, preserve in their silica-oxygen structure a determined ratio of light to heavy oxygen prevalent when they where alive. The isotope laboratory at the Alfred Wegener Institute in Potsdam is one of eight institutes worldwide working on a method to break down this molecular structure and analyse the oxygen released – the preserved climate of the past. Based on this data the researchers hope to be able to draw conclusions about how warm or cold it was during each period and what the prevalent wind systems were. Will they succeed in taking a glimpse into the past?