Real-time space observations can now monitor “over-emitting” power plants.

Countries that signed the 2015 Paris Agreement have pledged to keep the rise in average global temperatures “well below” 2 °C. Every five years, they will issue so-called “nationally determined contributions” (NDCs), outlining their actions to reduce greenhouse gas (GHG) emissions and adapt to the effects of climate change.

Thus, countries should monitor carbon emissions not only at the national level, but also at the scale of individual “super-emitters” such as power plants, megacities, refineries and giant factories—together responsible for nearly half of humanity’s total output. of greenhouse gases.

In late 2025 or 2026, the EU plans to launch its “CO2M” (Copernicus Anthropogenic CO₂ Monitoring Mission) pair of satellites, whose job will be to help with this.

Important proof of principle for CO2M

But now, scientists have shown that such monitoring at the source is already possible, even with existing satellites, for “super-emitters” such as the Bełchatów power station in Poland. For this proof of principle, they used five years of measurements from NASA’s “Orbiting Carbon Observatory 2” satellite (OCO-2; launched in 2014) and the OCO-3 instrument, which has been attached to the International Space Station (ISS) since 2019. .

This success is a significant achievement, as the OCO missions were designed to measure carbon emissions at much larger spatial scales.

“Here we show for the first time that it is already possible to measure changes in CO₂ emissions from a large power plant, with observations from existing CO₂– tracking satellites,” said Dr. Ray Nassar, an atmospheric scientist at Environment and Climate Change Canada in Toronto, and first author of the study, published in Frontiers in Remote Sensing.

The largest power plant in Europe

The Bełchatów Lignite Power Station is the largest thermal power station in Europe and the fifth largest in the world. Here, units are sometimes decommissioned and new ones commissioned, while more often units are temporarily shut down for maintenance. To be useful, satellites and instruments such as OCO-2 and OCO-3 must detect changes in CO immediately₂ emissions due to these changes in function—and here, Nassar and colleagues show for the first time that they can.

CO₂ emitted from the 300-meter-high stacks in Bełchatów and carried by the wind in the form of an invisible plume, about 10–50 km long and 550 meters above the Earth. OCO-2, which orbits the Earth at an altitude of 705 km, passes close to or directly over Bełchatów every 16 days. OCO-3 orbits at an altitude of 420 km and passes most often over or near Bełchatów. The OCO-3 has the added capability of scanning back and forth across an area, providing better local coverage or a wider view.

Not every crossing or crossing is suitable

Satellites can assess CO₂ “reinforcement” – additional CO₂ emitted from a source—only in the absence of clouds and when the plume does not pass over large bodies of water or mountains. They measure “XCO2”, the average CO₂ concentration in a column immediately below, subtracting the current background value (locally, average 415 ppm) around the plume.

Together, OCO-2 and OCO-3 yielded 10 suitable CO data sets₂ plume over Bełchatów between 2017 and 2022.

Excellent agreement between observed and predicted data

The researchers compared measurements from space with estimates of Bełchatów’s emissions, based on known daily energy production. The measurements were shown to closely track the daily forecasts. This proves that even today, existing satellites can monitor emissions in near real time for facilities like Bełchatów. For example, OCO-2 detected a sharp but transient drop in emissions from Bełchatów between June and September 2021 due to a maintenance shutdown.

All clean for CO2M

The results are promising: They indicate that CO2M, with a combined spatial coverage of about one hundred times that of OCO-2 and OCO-3, will be able to meet future needs.

“The ability to obtain the most accurate information on CO₂ emissions from ‘super-emitters’, such as the Bełchatów Power Plant, around the world will enhance transparency in carbon accounting and hopefully ultimately help reduce these emissions,” said Nassar.

“This future capability will lead to improved CO₂ information on emissions at the scale of countries, cities or individual facilities, enhancing transparency under the Paris Agreement and supporting efforts to reduce emissions that cause climate change.”