Nine massive methane leaks that satellites detected from natural gas pipeline infrastructure in Mexico over the last three years provided further evidence that methane emissions — one of the main drivers of global warming — are much higher than government estimates.
"There is a big discrepancy between the emissions that companies report and those observed in the atmosphere," Christian Lelong, director of climate solutions at geo-analytics company Kayrros, told Argus.
From 2019-2020, satellites detected huge plumes of invisible and odorless methane over gas pipelines running through the desert town of Mapimi in Durango and in China, Nuevo Leon, according to data from Kayrros.
The biggest leak — an eight-day event over gas pipelines in Mapimi during March and April 2019 — is even larger than the emission rate detected during a record leak from state-owned company Pemex's offshore Zaap oil platform last August. Scientists from the University of Valencia detected emissions of 100 metric tonnes (t)/h from the platform over various days in August, while the Mapimi leaks range from 99t/hr to 372t/hr.
But the leaks could be larger as each emitting event might last for hours or days, while cloud cover and humidity limit the imaging capacity of the satellite. Cenagas operates 10,336km of gas pipelines across Mexico, while 26 additional lines were sponsored by state power company CFE during the previous administration.
By cross-referencing the coordinates — with a 20km margin of error — provided by Kayrros' analysis of European Space Agency observations from the Sentinel-5P satellite with government energy infrastructure maps, Argus identified the possible sources of the Mapimi leaks. They could be gas pipeline operated by state-owned company Cenagas or the El Encino-La Laguna gas pipeline operated by private firm Fermaca. Both companies declined to comment.
Kayrros data also detected a 77 t/hr methane leak on 24 November 2020 near China, Nuevo Leon, close to gas pipelines operated by Cenagas and Sempra Infrastructure, subsidiary of US utility Sempra. While Cenagas declined to comment, Sempra Infrastructure said it had no record of gas being vented or released into the air from its pipeline or nearby compression station on that date.
"All of our natural gas transport assets are designed, built, operated and maintained in accordance with applicable standards and regulation," Sempra Infrastructure told Argus.
Methane is responsible for around 30pc of the rise in global temperatures since the Industrial Revolution, and quick and sustained emission reductions are key to limiting near-term warming and improving air quality, according to the International Energy Agency (IEA).
Oil and gas operations in Mexico emitted 1.47mn t of methane last year — from flaring, venting and fugitive emissions — that IEA says could be reduced without any net cost using existing technology.
Midstream and upstream operators in Mexico are required to submit six-year methane reduction plans as well as annual methane leak prevention and detection programs to ASEA but, with the advent of satellite technology from 2019, scientists have proven that self-reported emissions data is largely inaccurate.
Mexico's methane emissions are around 10 times higher than government reports, according to the Environmental Defense Fund.
But following years of unchecked flaring across state-owned Pemex's production assets, the Mexican government announced enhanced greenhouse gas emissions (GHG) reductions targets at the COP27 talks in Egypt on 12 November.
Mexico pledged to reduce GHG emissions by 35pc by 2030, up from the previous 22pc, as part of a $48bn program that will be partially funded by the US.
As part of the initiative, Pemex will work with the US Environmental Protection Agency to develop a methane emissions mitigation program for its onshore assets that will be published in the first half of 2023.
