nitrogen | EANET Acid Deposition Monitoring Network in East Asia

20 January 2026

The Sustainable Nitrogen Management Seminar 2025 – Accumulation of Nitrogen Data in EANET was held online on December 22, 2025 bringing together 58 participants. Organized under the EANET Project Fund Activity 2025-04 by the Network Center for the EANET, the seminar focused on strengthening the accumulation, analysis, and utilization of nitrogen-related data to address growing regional and global nitrogen pollution challenges.

Addressing Nitrogen Beyond Planetary Boundaries

The seminar opened with remarks underscoring nitrogen as a pollutant that has transgressed planetary boundaries, posing serious risks to ecosystems, human health, and climate. Speakers referred to the 2022 United Nations Environment Assembly (UNEA) Resolution on Sustainable Nitrogen Management that calls for sustainable nitrogen management worldwide. Against this backdrop, EANET’s role as a long-term regional monitoring network in East Asia was positioned as increasingly critical for evidence-based policymaking.

Moderated by Dr. Hiroyuki Sase of the Asia Center for Air Pollution Research (ACAP), serving as the Network Center for the EANET, the session highlighted how EANET’s Medium-Term Plan (MTP) 2026–2030 places nitrogen management as one of the core objectives. Dr. Toshimasa Ohara, Director General of ACAP, emphasized that EANET’s extensive datasets on atmospheric concentration and deposition offer a strong foundation for advancing sustainable nitrogen strategies and supporting international environmental cooperation.

Advancing Nitrogen Monitoring Science

The technical session showcased cutting-edge research and monitoring approaches. Professor Kazuhide Matsuda from Tokyo University of Agriculture and Technology presented an assessment of atmospheric nitrogen deposition using EANET data. He drew attention to the growing significance of reduced nitrogen (ammonia) and the challenges of accurately measuring it, particularly the artifact problems associated with traditional filter-pack methods. He proposed passive samplers as a practical, cost-effective option for expanding ammonia monitoring across rural and forested areas.

Complementing this, Dr. Yongjoo Choi from Hankuk University of Foreign Studies demonstrated how CrIS satellite data, combined with in-situ measurements and machine learning bias correction, can map ammonia concentrations with high spatial and temporal resolution. His findings revealed elevated ammonia levels over agricultural and livestock-intensive regions in Republic of Korea, especially during summer, illustrating the value of integrating satellite and ground-based observations.

Focus on Ammonia and Deposition Complexity

A major discussion theme was the complexity of ammonia (NH₃) deposition, particularly its bidirectional exchange between the atmosphere and ecosystems. Depending on environmental conditions, ammonia can be either deposited or re-emitted, complicating net flux estimates. Participants stressed the need for improved models, enhanced measurement techniques, and hybrid data approaches to better understand ammonia’s ecological impacts.

Strengthening Collaboration for the Future

In closing, Dr. Fan Meng, Deputy Director General of ACAP, thanked the speakers and participants for their active engagement. The seminar concluded with a shared understanding that enhanced monitoring, innovative data analysis, and international collaboration will be essential for managing reactive nitrogen pollution effectively across the EANET region.

Find out more about the EANET Project Fund.

Useful Resources:

–Event Summary

-Presentations:

Photo credits: Japan (2019) by Nomadic Julien.

nitrogen seminar

Bangkok, 23 February 2024

As a pre-seminar to UNEA-6, the Sustainable Nitrogen Management Seminar, addressed the significant yet underrepresented issue of nitrogen management in Asia and globally, and provided a platform for EANET Participating Countries to enhance their understanding of the nitrogen challenge. Organized virtually by EANET, with the support of the Ministry of the Environment, Japan, through the EANET Project Fund, the Seminar gathered around 100 participants. It aimed to explore strategies for sustainable nitrogen management through experts’ lectures and discuss the accumulation of nitrogen data within the EANET framework.

The seminar, facilitated by Ms. Aurélia Lemoine (Session 1) and by Bert Fabian (Session 2) from the Secretariat for the EANET, hosted by UNEP, started with an opening address by Mr. Yu Kamei, Director for International Cooperation at the Ministry of the Environment, Japan.

Global Trends and Insights

Dr. Ning Liu, Programme Management Officer, Source to Sea Pollution Unit, UNEP, presented updates on the UNEP Working Group on Nitrogen, highlighting the importance of collaborative efforts in addressing nitrogen-related challenges. Prof. Kentaro Hayashi, Professor, at the Research Institute for Humanity and Nature, Japan emphasized the interconnectedness of nitrogen issues with the atmosphere and the overall narrative surrounding nitrogen management.

Dr. Wilfried Winiwarter, a Senior Research Scholar from the Pollution Management Research Group, Energy, Climate, and Environment at the International Institute for Applied Systems Analysis (IIASA), Austria, presented the use of nitrogen budgets for sustainable management, highlighting comprehensive approaches to tackle nitrogen-related issues. Dr. Kazuya Nishina, a Senior Researcher at the Earth System Division (Biogeochemical Cycle Modeling and Analysis Section), from the National Institute for Environmental Studies (NIES), introduced the Japan Nitrogen Waste project, underlining the importance of national inventories in understanding nitrogen dynamics.

EANET’s Role in Nitrogen Management

Dr. Hiroyuki Sase, Head of the Ecological Impact Research Department, ACAP, presented the potential of EANET in contributing to sustainable nitrogen management, emphasizing the importance of monitoring nitrogen cycles comprehensively. Dr. Le Ngoc Cau, Deputy Director General, Viet Nam Institute of Meteorology, Hydrology and Climate Change (IMHEN), Ministry of Natural Resources and Environment Viet Nam, highlighted efforts in Viet Nam to identify and control nitrate pollution in water bodies, reflecting the global significance of nitrogen management.

The seminar featured Q&A sessions, where participants raised questions regarding the implications of ammonia as a new fuel and the role of nitrogen in European farming practices. Discussions revolved around the need for enhanced collaboration and the significance of localized approaches in nitrogen management strategies.

Moving Forward

Wrapping up Part I, Prof. Hayashi emphasized the pivotal role of EANET in addressing atmospheric aspects of nitrogen management, stressing its direct and indirect contributions to sustainable practices. Dr. Sase concluded Part II by highlighting EANET’s extensive data accumulation efforts, emphasizing its potential to understand nitrogen flows comprehensively. Experts reiterated the importance of EANET’s role in nitrogen management, emphasizing the need for continued collaboration and data-driven approaches.

Find out more about the EANET Project Fund

Useful Resources

Panelists’ Presentations

1. Update on UNEP Working Group on Nitrogen by Mr. Liu

2. The overall story about the nitrogen issue connected to the atmosphere by Prof. Hayashi

3. Using nitrogen budgets for sustainable nitrogen management by Dr. Winiwarter

4. The Potential of EANET to Contribute to Sustainable Nitrogen Management by Dr. Sase

Tag: nitrogen

Sustainable Nitrogen Management Seminar 2025 Highlights EANET’s Role in Tackling Nitrogen Pollution