NASA's Earth space instrument spots methane 'super-emitters'

When the Earth Surface Mineral Dust Source Investigation (EMIT) instrument was launched into space in July 2022, it was intended to map the mineral composition of arid dust source regions. The information procured would deepen our understanding of airborne dust’s effects on climate. But, EMIT went above and beyond the call of duty, identifying more than 50 "super-emitters" producing methane at high rates.

Super-emitters are facilities, equipment, and other infrastructure, mostly in the fossil fuel, waste, or agriculture sectors. In the data that EMIT has collected since being installed on the International Space Station in July, it spotted the emitters in Central Asia, the Middle East, and the Southwestern United States.

Methane, a greenhouse gas, is 80 times more potent than carbon dioxide. At least 25 percent of today's global warming is triggered by methane from human actions.

"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," NASA Administrator Bill Nelson said in a statement.

EMIT detected gigantic plumes - some of the largest ever seen

"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," he said.

With high accuracy and precision, EMIT's imaging spectrometer can recognize spectral fingerprints, which is a unique pattern in which methane absorbs infrared light.

Coincidentally, the mission's study area comprises well-known methane hotspots around the world, which enabled researchers to look for the gas in regions to "test the capability of the imaging spectrometer".

"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 at JPL leading the EMIT methane effort. "What we've found in just a short time already exceeds our expectations."

The Turkmenistan sources have a similar flow rate to the 2015 Aliso Canyon gas leak

For example, the instrument detected a plume about two miles (3.3 kilometers) long southeast of Carlsbad, New Mexico, in the Permian Basin, one of the largest oilfields in the world. Scientists estimate flow rates of about 40,300 pounds (18,300 kilograms) per hour at the Permian site.

If you think that's a lot, take the case of Turkmenistan. In the country, 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 20 miles (32 kilometers). The flow rates are about 111,000 pounds (50,400 kilograms) per hour in total for the Turkmenistan sources.

For comparison, the Turkmenistan sources together have a similar flow rate to the 2015 Aliso Canyon gas leak, which exceeded 110,000 pounds (50,000 kilograms) per hour at times. The Los Angeles-area disaster was among the largest methane releases in U.S. history.

The team also identified a methane plume south of Tehran, Iran, at least three miles (4.8 kilometers) long, from a major waste-processing complex. A byproduct of decomposition, methane can be largely found in landfills. The flow rates were 18,700 pounds (8,500 kilograms) per hour at the Iran site.

A key step toward acting on climate change

EMIT is expected to find hundreds of super-emitters, both previously spotted, and unknown others.

"As it continues to survey the planet, EMIT will observe places in which no one thought to look for greenhouse-gas emitters before, and it will find plumes that no one expects," said Robert Green, EMIT’s principal investigator at JPL.

Identifying methane point sources is a significant step toward limiting emissions.

"We have been eager to see how EMIT’s mineral data will improve climate modeling," said Kate Calvin, NASA’s chief scientist, and senior climate advisor. "This additional methane-detecting capability offers a remarkable opportunity to measure and monitor greenhouse gases that contribute to climate change."