 "Itziar Irakulis Loitxate")
By Aaron Clark
Like a detective gathering clues, Itziar Irakulis Loitxate scans her computer monitor looking for yellow-colored clouds in satellite data that suggest the presence of methane, a pernicious greenhouse gas that can escape from the Earth when coal, oil and fossil gas are produced.
The 27-year-old Ph.D. student isn’t a detective but she may be the closest thing the world has to climate police. She’s one of the world’s foremost remote sensing scientists who uses satellite observations to identify some of the most damaging emissions. She uncovered and published a paper last year on a massive release of methane spewing from an offshore oil and gas platform in the Gulf of Mexico that eventually forced government-owned Petroleos Mexicanos to acknowledge a leak. Before that, she identified 29 pieces of equipment in the central Asian country of Turkmenistan leaking so much methane they had a similar climate impact as the annual emissions from all the cars in Alabama.
As record temperatures threaten devastating ecological and human impact from Athens to Phoenix, governments are under increasing pressure to take measures to slow climate change. Because of methane’s short-term climate impact — the gas has more than 80 times the warming power of carbon dioxide in its first two decades in atmosphere — halting releases could do more to ease heating in the next few years than almost any other single measure.
That means the work of Irakulis Loitxate and fellow scientists who identify and attribute leaks is more important than ever. In September, she started work at the United Nations Environment Programme’s International Methane Emissions Observatory, including on a new initiative called the Methane Alert and Response System, or MARS, that notifies governments and companies to methane leaks from their fossil fuel infrastructure.
“When I find a plume I look for the source. When I know the source we can do something about it,’’ said Irakulis Loitxate (i-RA-kuu-lis loy-CHA-teh). IMEO has detected hundreds of methane clouds in dozens of countries and has alerted operators and governments in about half of the nations in which large emissions events have occurred. “More and more countries are trying to help us and improve the system and they are very receptive.’’
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Satellites detect concentrations of methane from space by observing the way sunlight reflects off the Earth. As light passes through a cloud of the gas, its intensity is weakened on certain wavelengths. Methane absorbs light in the short-wave infrared portion of the electromagnetic spectrum, which is invisible to humans.
To find clouds of the potent greenhouse gas Irakulis Loitxate works with scientists at SRON Netherlands Institute for Space Research who mine low-resolution imagery from the European Space Agency’s Sentinel-5P to identify global methane hotspots. Although the orbital only offers a rough approximation for where a plume might be coming from because of its course spatial resolution the satellite orbits the globe 14 times per day and provides global coverage.
Once Irakulis Loitxate has identified areas with potential emitters she searches for an image of the same area from high-resolution satellites like the Italian Space Agency’s Prisma or Germany’s EnMAP. These cover less ground but can offer close-up detail of methane clouds. Although those satellites weren’t explicitly built to observe the greenhouse gas, they have spectral bands that include the short-wave infrared and recent data processing innovations have allowed scientists to use them for precision imagery.
Because materials on the Earth’s surface can share portions of methane’s spectral profile, algorithms that process satellite data can occasionally have trouble distinguishing between these so-called artefacts and methane plumes, particularly for smaller emissions. To guard against false positives scientists typically check each plume before alerting an operator or government.
“In many cases, the emissions are challenging to identify even by humans if you don't have a well-trained eye and previous knowledge of the area you are studying,’’ said Irakulis Loitxate, who holds a research position at Polytechnic University of Valencia and expects to defend her Ph.D. by early next year.
Although agriculture is the biggest source of methane from human activity followed by energy and waste, halting the emissions from fossil fuels is some of the lowest hanging fruit in the fight against climate change because those releases typically come from large point sources and technology exists to halt them. IMEO is currently tracking roughly 125 fossil fuel hotspots located in 27 different countries.
IMEO has yet to publicly release the leaks it tracks but it intends to begin releasing some information by the end of this year. But a peek into observations from several methane-detecting satellites gives a sense of the hotspots that Irakulis Loitxate and her colleagues are likely trying to curb.
One area of focus is likely China, which the International Energy Agency estimates has more fossil fuel-related large leaks than any other country due to its coal operations. Sentinel-5P data shows a bleak history of dense clouds of the invisible gas frozen in mid-release after they escape from underground and surface mines. China has so far declined to join the US and EU-led Global Methane Pledge that has 150 signatories and the nation has said its pursuing its own mitigation approach. It has yet to release details publicly.
In the US Permian Basin, one the world’s largest active oil and gas reserves, clusters of observations are thick over parts of Texas and New Mexico. Although the US plans to implement new methane rules next year that will include fines for operators that exceed threshold limits, many operators still routinely vent the potent greenhouse gas directly into the atmosphere.
One objective of IMEO, through its MARS initiative, is to identify and halt so-called super emitters — large leaks that research shows accounts for as much as 12% of emissions from oil and gas production and transport. A recent leak in Kazakhstan captured by Sentinel-5P and the Prisma satellites illustrates the danger posed by these events. The release, which started June 9 after a natural gas well blowout, was ongoing as of Sept. 21 according to an analysis of satellite data from Kayrros SAS, which estimated an emissions rate of between 35 and 107 metric tons an hour. Assuming the release has been constant its short term climate impact is equivalent to the annual emissions from between 1.6 and 4.8 million US cars.
But the climate transparency generated by satellite observations and scientists like Irakulis Loitxate are expanding awareness of the devastating impact methane leaks have on the planet has started to trigger stronger action from officials.
“Governments and fossil fuel operators are more and more concerned about the problem with methane’’ said Irakulis Loitxate. “In some countries they weren’t concerned, but now, with a bit of training and education they realize that this is a big issue and they should do something.’’
