[PAOCQ] Hanqin Tian (BC)

“Toward a Predictive Understanding of Coupled Carbon–Nitrogen Cycles in the Earth System: A Scientific Journey”

The Earth system is shaped by largely invisible biogeochemical fluxes and pathways connecting land, water, and atmosphere. This presentation traces a scientific journey toward making these processes measurable, attributable, and predictable. Four turning points are highlighted: from single to multiple interacting environmental and human drivers; from carbon to integrated CO₂, CH₄, and N₂O budgets; from an overlooked N₂O cycle to comprehensive global assessment; and from terrestrial ecosystems to inland waters and the land–ocean continuum. Together, these advances demonstrate how connecting biogeochemical cycles, greenhouse gases, ecosystems, and human activities can deepen predictive understanding of the Earth system and inform climate mitigation and sustainability.

Hanqin Tian is an Institute Professor at Boston College, where he directs the Center for Earth System Science and Global Sustainability and the Boston Office of the Global Carbon Project (GCP). His research focuses on Earth system biogeochemistry, terrestrial biosphere modeling, and interactions among climate change, carbon, nitrogen, water, and human activities. Dr. Tian is a Clarivate Highly Cited Researcher with more than 500 scientific publications and an h-index of 130+. He received the 2025 AGU Bert Bolin Global Environmental Change Award and the 2026 Humboldt Research Award (Humboldt Prize). He is an Andrew Carnegie Fellow (Brainy Award) and Fellow of American Geophysical Union (AGU), the Ecological Society of America (ESA), and the American Association for the Advancement of Science (AAAS).

PAOC Colloquium —

Interdisciplinary seminar series that brings together the whole PAOC (Program in Atmospheres, Oceans, and Climate) community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, as well as talks about societal impacts of climatic processes.

Contact: paoc-colloquium-comm@mit.edu