Tue. May 27, 2025 1:45 PM - 3:15 PM Exhibition Hall Special Setting (3) (Exhibition Hall 7&8, Makuhari Messe)

convener:Kazuhito Ichii(Chiba University), Prabir Patra(Principal Scientist at Research Institute for Global Change, JAMSTEC and Professor at Research Institute for Humanity and Nature), Akihiko Ito(University of Tokyo), Oksana Tarasova(World Meteorological Organization), Chairperson:Kazuhito Ichii(Chiba University)

The Paris Agreement under the United Nations Framework Convention on Climate Change (UNFCCC) is a landmark agreement, which aims at reduction of greenhouse gases (GHGs) emission to keep the global warming below 2 deg C. The national commitments and progresses should be carefully monitored and verified by international bodies using different but complementary methodologies. Many observations and techniques to monitor GHGs budget have been improved in recent years, e.g. atmospheric inverse analysis, process-based models, and national statistics for inventories. As the demand for on time delivery of many of these products at low latency has increased from different stakeholders, the product delivery and accuracy assessment is being discussed at WMO and GCP activities. However, due to uncertainties in sparse observation network and integration methods, large uncertainty remains in GHGs sources/sinks estimations at global and regional scales. The purpose of the session is to discuss state-of-the-art techniques for estimations of GHGs (e.g. CO2, CH4, N2O) budget at global and regional scales. The topic includes natural and anthropogenic processes, various methodologies (e.g. in-situ observation, aircraft monitoring, remote sensing, modeling, integration), and various targets (e.g. atmosphere, land, and ocean), various spatial and temporal coverage (e.g. local-global and past-present-future). Optimization of observation locations for maximum benefit of flux uncertainty reduction (intelligent network design) is encouraged in this context. Improved estimates of emissions from land use change, biomass burning, and other anthropogenic sources are also of interest.