Articles | Volume 18, issue 18
https://doi.org/10.5194/amt-18-4871-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/amt-18-4871-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
29 Sep 2025
Research article |
| 29 Sep 2025
| 29 Sep 2025
A 30-month field evaluation of low-cost CO2 sensors using a reference instrument
Qixiang Cai
State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
Key Laboratory of Urban Meteorology, China Meteorological Administration, Beijing 100089, China
Carbon Research Center, Qiluzhongke Institute of Carbon Neutrality, Jinan 250100, China
Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland 20742, USA
Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland 20742, USA
Xiaoyu Yang
Department of Ecology and Remote Sensing, Shandong Jinan Ecological and Environmental Monitoring Center, Jinan 250102, China
Chi Xu
State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring, China National Environmental Monitoring Centre, Bejing 100012, China
Zhaojun Wang
Department of Ecology and Remote Sensing, Shandong Jinan Ecological and Environmental Monitoring Center, Jinan 250102, China
State Key Laboratory of Atmospheric Environment and Extreme Meteorology, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
Carbon Neutrality Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
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CH4 is a potent greenhouse gas, and China’s anthropogenic CH4 emissions account for a large proportion of global total emissions. However, the existing estimates either focus on a specific sector or lag behind real time by several years. We collected and analyzed 12 datasets and compared them to reveal the spatiotemporal changes and their uncertainties. We further estimated the emissions from 1990–2019, and the estimates showed a robust trend in recent years when compared to top-down results.
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Short summary
Mid- and low-cost CO2 sensors are attractive in carbon monitoring and atmospheric inversions. They are useful in both fixed stations and mobile monitoring. Yet the performance faces great challenges due to environmental impacts and long-term drifts. Here, we conducted 30 months of co-located observations using such sensors with a reference instrument. After corrections of environmental impacts and drifts, the accuracy reached 1–3 ppm. We recommend standard gas calibration within 3–6 months.
Mid- and low-cost CO2 sensors are attractive in carbon monitoring and atmospheric inversions....
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