Reliable and accurate monitoring of CO 2 emissions is a cornerstone of effective climate change mitigation strategies. While traditional methods largely depend on ground-based measurements and bottom-up inventories, these approaches are often resource-intensive and prone to errors. Satellite Technology has emerged as a promising alternative, but the challenge remains in distinguishing anthropogenic emissions from natural processes. The long atmospheric lifetime of CO 2 makes it difficult to pinpoint localized sources of emissions and track changes over time. Additionally, natural emissions and background concentrations can obscure signals from human activity. To overcome these hurdles, new, more advanced monitoring techniques are needed.
On October 18, 2024, a team from Tsinghua University published a review (DOI: 10.1007/s11783-025-1922-x) in Frontiers of Environmental Science & Engineering , presenting a novel method to monitor fossil fuel CO 2 emissions by utilizing satellite observations of NO 2 . This method offers a more reliable and scalable solution for tracking emissions, from localized sources like power plants to broader national levels.
The review introduces two primary methodologies to use NO 2 as a proxy for CO 2 emissions, taking advantage of its shorter atmospheric lifetime and enhanced detectability. The first method, the plume-based approach, uses NO 2 observations to locate and validate CO 2 plumes, providing a precise way to identify emissions from point sources such as power plants and industrial facilities. By tracking the movement of NO 2 plumes, researchers can more accurately determine the origin and magnitude of CO 2 emissions. This method is particularly useful in urban environments with multiple emission sources, as it allows for the differentiation of emissions from various facilities.
The second method, the emission ratio-based approach, involves estimating NO x emissions from NO 2 data and converting these estimates into CO 2 emissions using known CO 2 -to-NO x emission ratios. This technique is especially effective for larger spatial scales, such as national or regional assessments, where direct CO 2 observations might be compromised by high background concentrations. By incorporating emission ratios, this method accounts for variations in fuel types and combustion processes, offering a more reliable estimation of CO 2 e missions. The study also addresses the uncertainties inherent in these methods, including structural uncertainties in the relationship between NO 2 and emissions, as well as data-related challenges like retrieval errors and the accuracy of prior emissions inventories. To reduce these uncertainties, the researchers recommend the deployment of next-generation satellites with enhanced capabilities and the development of more sophisticated inversion systems.
Dr. Bo Zheng, an associate professor at Tsinghua University and a leading author of the study, commented, "This research marks a significant leap forward in our ability to monitor and verify CO 2 emissions. By utilizing NO 2 as a proxy, we can achieve much greater accuracy and reliability in emission estimates, which is crucial for implementing effective climate policies."
The study’s findings have far-reaching implications for global climate policy and environmental management. Accurate emissions monitoring is critical for countries to assess their progress toward meeting their climate commitments under the Paris Agreement. This new technology can support the development of more targeted and effective mitigation strategies, strengthening international efforts to combat climate change. Moreover, it provides researchers and policymakers with a valuable tool for understanding CO 2 emission dynamics and their environmental consequences, paving the way for more informed decision-making in climate action.
Frontiers of Environmental Science & Engineering
Experimental study
Not applicable
Monitoring fossil fuel CO2 emissions from co-emitted NO2 observed from space: progress, challenges, and future perspectives
18-Oct-2024