Satellite Tracks Carbon Polluters from Space

Attention greenhouse gas emitters:  There’s a new eye in the sky that will soon be photographing your carbon footprint and selling the images to any and all.  It’s a micro-satellite dubbed “Claire” (clear, bright, and clean in French) by its Montreal-based developer, GHGSat.

This microwave-oven-sized pollution paparazzo rocketed to a 512-kilometer-high (318 mi) orbit in mid-June care of the Indian Space Agency, with a mission to remotely measure the plumes of carbon dioxide and methane wafting up from myriad sources on Earth’s surface.  Claire's targets include power plants, natural gas fracking fields, rice paddies, and much more—just about any emissions source that someone with a checkbook (corporations, regulators, activists) wants tracked, according to GHGSat president Stéphane Germain.

Germain says Claire’s data can improve compliance reporting to regulators and carbon markets, enable tracking of industrial efficiency, and provide competitive intelligence, among other uses.  "Our vision is to be the global standard for emissions monitoring across the world. That’s ambitious, but we think it's attainable,” he says.

Space agencies already monitor emissions from orbit.  They have launched a series of satellites such as NASA’s OCO-2 to specifically track atmospheric CO2 and methane, and those missions are delivering an important reality check on national pollution inventories, which are based largely on engineering estimates. 

Both satellite and ground-based research has identified vast undercounting of methane emissions by the U.S. EPA, prompting the agency to revise its inventories earlier this year.

However, OCO-2 and other satellites such as Europe’s Tropomi and Japan's Ibuki were primarily designed to generate data for climate models, and thus emphasize a wide field and exquisite greenhouse-gas level precision but with low spatial resolution.  Germain says GHGSat is designed for a totally different mission. 

"We have deliberately limited the scope of the physical field of view.  We know where the emissions are coming from.  All we need to do is point at known sites and characterize the plume from the facilities," says Germain.

Like its predecessors, Claire uses an infrared spectrometer to detect telltale patterns of sunlight absorption that indicate levels of atmospheric CO2 and methane.  Unlike its predecessors, which use “push-broom” spectrometers that scan side to side to generate a 2-D spectral database, Claire has an imaging spectrometer that takes a series of 2-D spectral snapshots as the micro-satellite passes overhead.

Telescopic lensing focuses Claire's spectrometer to take 12 kilometer x 12 kilometer snapshots.  With its 0.25 megapixel detector, each pixel thus represents a 25 meter x 25 meter plot of ground—a spatial resolution two orders of magnitude higher resolution than OCO-2.

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