The smart people over at NASA's Jet Propulsion Laboratory have developed a new way to measure pollution in big cities and the results are a little scary: methane levels in Los Angeles are up to 61 percent higher than previously thought and 18 percent higher than even the most pessimistic view of LA's air quality. Methane is a greenhouse gas that comes from auto emissions, landfills, and wastewater treatment plants; while there's way less methane than carbon dioxide in the atmosphere, methane has a more severe effect on global warming—"it packs a much bigger punch, particularly on short timescales," according to the JPL press release. The measurements come from an instrument that observes the greenhouse gas levels in the LA basin from its perch above the pollution on Mt. Wilson.
The image above shows the fancy instrument, which lives in a not-so-fancy home (a shipping container). The machine measures methane and carbon dioxide levels at 29 points around Los Angeles, including Angels Stadium and the Santa Anita racetrack in Arcadia. The highest levels of methane were measured near the Rose Bowl in Pasadena and in eastern LA County. JPL says their new instrument is better than satellites for measuring gas concentrations around a big city, since similar instruments in space will only pass over a city once a day or week. The machine's estimated precision less than 0.5 percent, which seems pretty darn good.
· NASA Mountaintop Sensor Finds High Methane over LA [JPL]
· Scientists Creating Super-Detailed Emissions Profile of LA [Curbed LA]
· Mapping Los Angeles's Better But Still Terrible Air Quality [Curbed LA]