The Multi-resolution Emission Inventory model for Climate and air pollution research (MEIC) is a modeling platform of atmospheric emissions from anthropogenic sources, developed from the Multi-resolution Emission Inventory for China. MEIC, established and maintained by Tsinghua University since 2010, is designed for high-resolution multi-scale global databases of anthropogenic emissions of greenhouse gases and air pollutants. MEIC shares emission data products with scientific communities through the cloud computing platform in order to provide data support for scientific research, policy assessment, and air quality management.

Objective >

The emergence and evolution of a series of climatic and environmental problems, including climate change, ice sheet destruction, stratospheric ozone depletion, photochemical pollution, and haze pollution, are all associated with various greenhouse gases and pollutants emitted into the atmosphere from human activities. Thus, accurate quantification of emission fluxes and spatiotemporal distributions, characterization and projection of spatiotemporal changes in emission, and exploration of mechanism of anthropogenic impact on emission evolution, are all frontier research questions in the field of atmospheric science and climate change as well as the common challenges faced by all the human society and major requires of the construction of ecological civilization in China.

China’s system of emission source categories has the most complex technological composition and the fastest spatiotemporal changes in the world. Thus raising high technical requirements for the accurate quantification, timely updating, and high-resolution characterization of atmospheric emissions from human activities. During the past two decades, Tsinghua University has made great progress in the quantitative characterization of atmospheric composition emissions, benefited from the long-term support from 863 Program, 973 Program, National Key Research and Development Plan, National Natural Science Foundation of China, the National Research Program for Key Issues in Air Pollution Control, et al. A technical framework of high-spatiotemporal-resolution emission inventories for air pollutants has been built, conforming to China’s actual conditions with its own technical characteristics and with completely independent intellectual property rights. Under this technical framework, Tsinghua University has developed the Multi-resolution Emission Inventory for China (MEIC-China). MEIC-China constructed the unified emission source categories system, the localized emission factor database, and the technology- and dynamic-process-based approaches for emission characterization. A multi-scale and high-resolution gridded emission source model has been developed as well, which could seamlessly connected to mainstream atmospheric chemistry models. MEIC-China supports real-time dynamic computing and online downloading of emission data through the integration of cloud computing and big data technology.

On the basis of MEIC-China, the MEIC team cooperates with the team of China Emission Accounts and Datasets (CEADs), Chinese Academy of Environmental Planning of the Ministry of Ecology and Environment, and other institutions and research teams, to develop intelligent fusion and modeling technologies of multi-source big data as well as establish big-data-based original methods for dynamic emission characterization with high spatial and temporal resolution. As a result, the Multi-resolution Emission Inventory model for Climate and air pollution research (also referred to as MEIC for short) has been established to meet the needs of global climate and air pollution research. MEIC builds a global multi-scale atmospheric emission database with long time series, high spatial and temporal resolution, and dynamic updates, aiming to promote China’s research in the field of global atmospheric emission accounting, and provide emission data supporting global climate change and air pollution research.

MEIC provides data on atmospheric emissions from human activities at multiple scales worldwide through the online platform. At present, the downloadable emission data includes:

1. Global CO₂ emissions from fossil fuel combustion and cement process since 1970

2. Emissions of nine air pollutants and CO₂ since 1990 in China

3. China’s future emission scenarios and datasets in 2015-2060

4. Various atmospheric emissions datasets shared by the scientific community through the online data platform

The anthropogenic emission data developed based on the MEIC model has been widely used by numerous research institutes and operational organizations around the world. It has supported a number of large international research projects such as MICS-ASIA, HTAP, and CEDS. In China, it has been widely used in scientific research and operational work, such as air pollution source apportionment, air quality forecast and early warning, and assessment of air pollution control policies.

The MEIC team will continuously make great efforts to develop MEIC into an open-access and world-class research platform that provides high-accuracy, high-resolution, and timely-updated global atmospheric emission data to support scientific research and policymaking.

Features >

• Use unified methodology and dataset to assure transparency and comparability. Version management for code and data. Continuously dynamic updates.
• Integrate the most up-to-date methodology for dynamic emission characterization and localized emission factor database.
• Provide model-ready gridded emission input with multiple scales and components for air quality and climate modeling.
• Provide online calculation and download of emission data through cloud computing and big data technology.
• Support the coupling of multi-source emission inventories to generate emission reanalysis data products in a unified format.

Histories >

The MEIC has been developed since 2010. Five versions are available at present through continuous iterative development:

• Version v1.0 was published in 2012. In this version, the basic technical framework of MEIC model was constructed and the multi-pollutant emission inventory of China from 1990 to 2010 was compiled.
• Version v1.2 was published in 2015. In this version, the MEIC website was online to provide calculation and download of gridded emissions data based on the cloud computing and big data platform. Meanwhile, the basic input data such as energy consumptions and emission factors were systematically revised, and the spatiotemporal allocation proxies of emissions were updated. The emission inventory of China was updated to 2012.
• Version v1.3 was published in 2018. In this version, the anthropogenic emission trends since the implementation of the Clean Air Action in China were accurately quantified. The emission inventory of China was updated to 2017.
• Version v1.4 was finished in 2021. In this version, the impact from implementation of China’s Three-Year Action Plan for Winning the Blue Sky Defense Battle (the Three-year Plan) were comprehensively evaluated and the emission characterization of cement and rural residential sector was updated. The emission inventory of air pollution and CO₂ of China was updated to 2020.
• Version v2.0 was published in 2022. In this version, we upgraded the cloud computing and big data platform to support the reanalysis and sharing of multi-scale emission inventories. The MEIC was extended to global scale, and provided global CO₂ emissions from fossil fuel combustion and cement process in 1970-2021. For China, we optimized the emission characterization of key sources such as iron, steel industry and cement industry, and updated the emission inventory to 2021. The emission time series since 1990 were also updated.

Development team >

The MEIC model is developed and maintained by the following organizations and teams:

• Tsinghua University
• China Carbon Emission Accounts and Datasets (CEADs) team
• Chinese Academy of Environmental Planning of the Ministry of Ecology and Environment

Supporting organizations >

The development and maintenance of the MEIC model are sponsored by:

• China’s National High Technology Research and Development Program (863 Program)
• China’s National Basic Research Program (973 Program)
• China’s National Key R&D Programmes
• National Natural Science Foundation of China
• The public welfare program of China’s Ministry of Environmental Protection
• National Research Program for Key Issues in Air Pollution Control
• Tsinghua University Initiative Research Program
• Energy Foundation China
• State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex
• Ministry of Education Key Laboratory for Earth System Modeling