The agency’s Earth Surface Mineral Dust Source Investigation (EMIT) mission is mapping the prevalence of key minerals in the planet’s dust-producing deserts – information that will advance our understanding of airborne dust’s effects on climate.
But EMIT has demonstrated that it is also good at detecting the presence of methane, which is estimated to be 80 times more effective, ton for ton, at trapping heat in the atmosphere than carbon dioxide in the 20 years after release.
Nevertheless, while carbon dioxide lingers for centuries in the Earth’s atmosphere, methane only persists for about a decade, meaning that if emissions are reduced, global warming effects could also be slowed in a comparatively short timeframe.
The device, which is called an imaging spectrometer, has identified more than 50 ‘super-emitters’ in Central Asia, the Middle East and the south-western United States.
Super-emitters are facilities, equipment and other infrastructure, typically in the fossil-fuel, waste or agriculture sectors, that emit methane at high rates.
“Reining in methane emissions is key to limiting global warming. This exciting new development will not only help researchers better pinpoint where methane leaks are coming from, but also provide insight on how they can be addressed – quickly,” said Nasa administrator Bill Nelson.
“The International Space Station and Nasa’s more than two dozen satellites and instruments in space have long been invaluable in determining changes to the Earth’s climate. EMIT is proving to be a critical tool in our toolbox to measure this potent greenhouse gas – and stop it at the source.”
Methane absorbs infrared light in a unique pattern – called a spectral fingerprint – that EMIT’s imaging spectrometer can discern with high accuracy and precision. The instrument can also measure carbon dioxide.
The new observations stem from the broad coverage of the planet afforded by the space station’s orbit, as well as from EMIT’s ability to scan swathes of the Earth’s surface dozens of miles wide while resolving areas as small as a soccer field.
“These results are exceptional, and they demonstrate the value of pairing global-scale perspective with the resolution required to identify methane point sources, down to the facility scale,” said David Thompson, EMIT’s instrument scientist. “It’s a unique capability that will raise the bar on efforts to attribute methane sources and mitigate emissions from human activities.”
With knowledge of the locations of big emitters, operators of facilities, equipment and infrastructure giving off the gas can quickly act to limit emissions.
Over its mission, EMIT will also collect measurements of surface minerals in arid regions of Africa, Asia, North and South America, and Australia.
“Some of the plumes EMIT detected are among the largest ever seen – unlike anything that has ever been observed from space,” said Andrew Thorpe, a research technologist leading the EMIT methane effort. “What we’ve found in a just a short time already exceeds our expectations.”
For example, the instrument detected a plume about 3.3km long south-east of Carlsbad, New Mexico, in the Permian Basin. One of the largest oilfields in the world, the Permian spans parts of south-eastern New Mexico and western Texas.
In Turkmenistan, EMIT identified 12 plumes from oil and gas infrastructure east of the Caspian Sea port city of Hazar. Blowing to the west, some plumes stretch more than 32km.