Pep is the Executive Director of the Global Carbon Project, focusing on highly integrative and interdisciplinary research on global and regional analyses of trends, drivers and budgets of the sources and sinks of the main greenhouse gases. He also studies the size and vulnerability of earth’s carbon pools, carbon-climate feedbacks, and pathways to stabilize the climate, including nature-based solutions and negative emissions technologies. More recently, he has also focused on abrupt ecosystem changes and collapse due to rapid climate change, including the role of fire.