AOSC Seminar by Dr. Hanqin Tian, 4/21/2022
Dr. Hanqin Tian
University of Auburn
Title: How can the terrestrial biosphere be a part of the climate solution? Toward a predictive understanding of the global carbon cycle and GHG budgets
The land biosphere plays a major natural contribution to climate stability by removing around one third of anthropogenic CO2 emissions from the atmosphere each year (IPCC 2021). However, human disturbances of the land biosphere such as anthropogenic nitrogen enrichment and land transformation have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in the emissions of non-CO2 greenhouse gases (CH4 and N2O) in particular can contribute to climate change. By considering all three major GHGs (CO2, CH4 and N2O ) together, i.e. a net GHG balance of the land biosphere, our study shows that the cumulative warming capacity of concurrent biogenic CH4 and N2O is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake in the 2000s. Agriculture and waste are the largest contributor to this twofold offset of the land CO2 sink. Land-use intensification using today’s practices to meet food and energy demands increases anthropogenic GHG emissions, which is not consistent with stabilizing the climate at low temperature scenarios. To reverse the land biosphere’s current warming role, it is essential to adopt climate-smart agricultural practices to enhance carbon storage as well as reduce non-CO2 GHG emissions. The future role of the land biosphere as a source or sink of GHGs will depend on future land-use intensification pathways and on the evolution of the land CO2 sinks. Therefore, how we manage the global lands needs to become a central part in our strategy to mitigate climate change.
Dr. Hanqin Tian is Solon & Martha Dixon Professor, Director of International Center for Climate and Global Change Research, and Leader for interdisciplinary cluster of CHESS (Climate, Human and Earth System Sciences) at Auburn University. His primary research interest focuses on a predictive understanding of biosphere’s roles in global biogeochemical cycles and greenhouse gas budgets. His research has resulted in over 300 peer-reviewed journal papers including 30 papers in Nature/Science/PNAS and their sister journals with a citation of 33,000 and H-index of 87. His pioneering work on the global carbon and nitrogen cycles and greenhouse gas emissions is at the leading edge of the field. He has served on Scientific Steering Committee of the Global Carbon Project (GCP) and Co-Chair of the international consortium of GCP-INI (International Nitrogen Initiative) for global nitrous oxide assessment. As elected Fellow of AGU, ESA and AAAS, Dr. Tian is recognized a world leader in quantifying global carbon and GHG budgets.
Contact: Xin-Zhong Liang
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Pre-seminar refreshment: N/A
Seminar: 3:30-4:30pm, Room: ATL 2400(only when in-person)
Meet-the-Speaker: 4:30-5:00pm, Room: ATL 3400(only when in-person) [For AOSC Students only]