Birger holds a PhD in sedimentary petrology, clastic diagenesis and petroleum geology. Following several years in the petroleum industry as a development geologist, Birger was awarded an Australian Postdoctoral Fellowship by the Australian Research Council (ARC), based on the use of radioactive bitumen nodules and oil-bearing fluid inclusions to trace oil migration in ancient sedimentary basins. During a subsequent ARC QEII Fellowship, he studied the impact of diagenetic phosphates on marine phosphorus and rare-earth element cycles, and their potential for dating ancient biological and environmental events. In 2007, Birger joined Curtin University as a Research Professor. In 2011, Birger was awarded an ARC Australian Professorial Fellowship to investigate the early history of atmospheric oxygen.