The amount of carbon dioxide emitted by a power plant is revealed in this image taken on Nov. 1 by Montreal-based GHGSat. The detector uses the absorption of infrared light to measure concentrations of CO2 in the atmosphere, which can be superimposed onto satellite photos of the corresopnding location. The company's system can identify, monitor and verify CO2 emissions from industrial sources around the globe.GHGSat
The world may be struggling mightily to rein in emissions of carbon dioxide that are the main driver of climate change, but a technology that can show where those emissions originate is leaping forward.
The latest evidence of this comes from Montreal-based GHGSat Inc., which uses satellite-borne detectors to measure greenhouse gas emissions from sources on Earth. Since 2016, the company has made its name by spotting methane leaking from industrial sites and landfills around the globe. Last year GHGSat launched Vanguard, the first commercial satellite built to measure CO2 in a consistent way.
On Friday, the company demonstrated Vanguard’s capabilities at COP29, the United Nations climate conference currently under way in Baku, Azerbaijan. The first publicly released image from Vanguard shows a plume of carbon dioxide streaming from a power plant.
GHGSat does not publicly disclose the locations of the sites it measures but instead works with clients to provide verification of how much carbon is being emitted and where. The Globe and Mail independently determined that features in the image match those of a site in western China.
Although CO2 is invisible to the eye, it absorbs infrared light. As Vanguard passes overhead, the satellite can use this property to calculate excess levels of carbon dioxide in parcels of air just 30 metres across. The method is ideal for quantifying emissions from discrete sources, including industrial sides.
For example, the newly released image shows that the amount being released by the power plant when the data was taken on Nov. 1 corresponds to an emission rate of 12 megatonnes per year. In practice, the satellite would combine measurements made over multiple passes to establish an average emission rate.
Stéphane Germaine, founder and chief executive officer of GHGSat, said the satellite data makes it possible to compare emissions in a way that is consistent for every location on Earth.
“Our goal is to work with operators and governments to verify their own estimates of emissions,” he said. “We suspect that the estimates won’t be the same as the measurements and that this will be true all over the world – we’re just showing one example here.”
With a dozen satellites in orbit, 11 of which detect methane, the company has maintained its position as the most comprehensive eye for measuring emissions. Two additional launches are scheduled for next summer, with more to follow in 2026.
Meanwhile, Carbon Mapper, a U.S.-based not-for-profit company, is now providing open-source emissions data from its first satellite, named Tanager-1, which launched in August.
The satellites are all looking down on a world where emissions, so far, continue to increase, according to the latest report this week from the Global Carbon Project, led by the University of Exeter in Britain.
But Mr. Germaine, who is attending his fourth UN climate conference, said satellites are having an impact on negotiations.
“It’s absolutely changing attitudes,” he said. “People now know that the whole world is being monitored on a near daily basis.”