🛰️ Reducing CO2 emissions from fossil fuel combustion is key to controlling global warming, a key goal of the UNFCCC Paris Agreement. Approximately half of global CO2 emissions of fossil fuels comes from large installations such as power plants. To promote transparency under the Paris Agreement, an observation-based approach to quantifying emissions from these installations could be useful.

A recent study aimed to quantify CO2 emissions from Europe’s largest fossil fuel power plant, the Bełchatów Power Plant in Poland. The scientists used CO2 data from NASA’s Orbiting Carbon Observatory (OCO-2 and OCO-3) missions, collected over ten flybys between 2017 and 2022.

Space-based monitoring of CO2 emissions

The OCO-2 and OCO-3 satellites measure atmospheric CO2 (XCO2). OCO-2, launched in 2014, observes from an orbit with limited imaging capabilities, measuring XCO2 in a narrow band. OCO-3, launched to the International Space Station (ISS) in 2019, has enhanced scanning capabilities through the Snapshot Area Mapping (SAM) feature, which allows it to acquire XCO2 images over an area the size of a city.

To estimate emissions from the Bełchatów power plant, the scientists used measured XCO2 values and applied the Gaussian plume model. This model simulates the dispersion of CO2 depending on wind speed and direction, as well as atmospheric stability. To calculate emissions, it is important to accurately determine the “background” value – i.e. the typical CO2 concentration in the surrounding area that is not affected by emissions from the power plant. The study examined different methods of defining the background and the associated uncertainties to better understand their impact on the results.

Results and verification of emission reductions

The study analyzed one OCO-2 flyby from March 2017 and nine OCO-3 (in SAM mode) flybys from 2020-2022. Space-based estimates of CO2 emissions showed changes in emissions with a trend that is consistent with independently reported hourly energy production trendThese changes in energy production are the result of both permanent and temporary shutdowns of power plant units.

Emission estimates from OCO-2 and OCO-3 agree with independent emission estimates within their respective 1σ uncertainties in 9 out of 10 cases. This agreement is significant and demonstrates the ability of existing satellite CO2 observations to quantify emission reductions for large facilities, given sufficient coverage and frequent flybys.

The first space-based evidence of emissions reduction

This work presents first space-based observational evidence of anthropogenic CO2 emissions reductions at the single facility levelThis demonstrates the feasibility of facility-level emissions monitoring to support efforts to track CO2 emission reductions under the Paris Agreement.

The results of the study are informative for understanding the expected capabilities and potential limitations of the planned Copernicus Anthropogenic CO2 Monitoring (CO2M) mission and other future satellites. The CO2M mission, scheduled for launch in 2025–2026, is designed to enable monitoring and verification (MVS) capabilities far beyond the capabilities of current missions. One of the main objectives of CO2M is to detect and monitor emission hotspots, such as power plants, to assess emission reductions/increases and track the impact of Nationally Determined Contributions (NDCs) under the Paris Agreement.

The study also highlights areas where further improvement is needed to reduce uncertainties in the quantification of CO2 emissions from space, particularly in the accuracy of XCO2 data acquisition and the quality of external meteorological (wind) data. Despite some limitations, this emerging monitoring and verification (MVS) capability can play a role important role in supporting the reduction of anthropogenic CO2 emissions in order to achieve the goals set out in the Paris Agreement. Spring