Science Magazine: California to hunt greenhouse gas leaks and superemitters with monitoring satellites

“ The announcement has the potential to “shake up” the field of greenhouse gas monitoring and verification, says Ray Nassar, an atmospheric scientist unaffiliated with the project at Environment and Climate Change Canada. He says the satellites would be immediately useful for tracking fugitive methane emissions, which have more than 80 times the warming power of CO2 emissions in the short term. “Finding, pinpointing, and stopping the big leaks is thus key,” he says. The satellites will be built and managed by Planet, a California company that already operates a constellation of Earth-imaging satellites. The spacecraft will rely on “hyperspectral” imaging spectrometers developed by NASA’s Jet Propulsion Laboratory (JPL). Rather than gathering light in just a few discrete wavelength channels, like the human eye, these spectrometers capture reflected sunlight and subdivide it into more than 400 wavelength channels across the visible and into the infrared. The intensity of light across these channels can be tied to specific chemistries and reflect the abundances of certain gases in the air molecules below. “It’s a molecular mapping system,” says Greg Asner, an ecologist at Arizona State University, Tempe, who will lead many of Carbon Mapper’s scientific applications.”