Why are there so many methane satellites?

Monitoring from the ground using methane sensors that detect the gas directly requires a lot of human labor. You need to send people out to often remote locations to set up bulky tripods full of (still expensive) sensors. You need some expensive data backhaul because these places often don’t have cellular access. We were billed by the byte to have a 24/7 contract with uptime guarantees in some of these locations. One big issue is that the companies paying for self-monitoring want suspiciously low false positives (for legal compliance reasons). You have to work with the land owners if you expect them to let you put sensors on their sites. This limits who can access that data compared to a NGO running a satellite, and requires you to filter out “noise” that’s probably not noise to appease the customers. They’re also not very accurate at detecting source in that close distance. Gases tend to quickly rise above where a human can place a sensor array and the wind and environmental factors play a huge impact. Very few companies are willing to stand behind their physics modeling with any kind of SLA. The human cost also shouldn’t be understated: when my coworkers would go and set up these sensors they’d be dizzy for days/weeks due to the emitted gasses they breathed in, our employer basically couldn’t find affordable medical insurance for us.

If you want to use spectroscopy/cameras, you can do it from a (small) distance. But it’s fantastically expensive equipment that only can be used for 1 site. And the “looking up” angle is worse than “looking down”. It’s an open question in the industry if the data can be trusted from these setups. You still have a lot of the complexity of maintaining them and exfiltrating the data.

If you want to just fly a plane… that’s expensive, you need to do it regularly, you still have a lot of “not actively monitored” time, etc.

The customer antennas would make poor radio telescope because the antennas are small. If using array of small antennas as radio telescopes were possible, we would see them. Using interferometry requires measuring positions and times to sub-wavelength. The Square Kilometer Array is the closest, but it is small extent, with large dishes, and many low-frequency antennas.

1: https://pbs.twimg.com/media/DTW_zc_W0AEH3Un?format=jpg&name=...

Accelerating the "natural" cycle is bad even if there is no net increase. A massive forest fire technically doesn't cause any net increase in CO2, but releasing that much CO2 at once causes a lot of problems that wouldn't happen if the same amount were released over hundreds of years as those trees died and decayed.

I'm sure some people would argue that burning oil and gas isn't a net increase either, because all of that carbon came from the atmosphere originally. The important question is what emissions will make life worse for humanity, and what can be done to avoid them. Avoidable methane emissions cause real-world problems regardless of their source.

From a layman's perspective:

(1) the incentive is not aligned to accurately report leaks [1][2][3][4][5]

(2) Satellites provide global monitoring. This reaches to places/countries/regions that are not regulated, and secondly provides monitoring for natural sources of methane emissions (eg: permafrost). For the latter, even if there is nothing to be done about natural emissions, the more accurate data will provide for better modelling and help humans better understand the Earth's ecosystem.

[1] June 2022: "Oil and gas companies underreported methane leaks, new study shows" https://www.washingtonpost.com/climate-environment/2022/06/0...

[2] Oct 2023: "Oil and gas companies are missing significant methane emissions. Here’s how to fix that." https://rmi.org/oil-and-gas-companies-are-missing-significan...

[3] "Gross under-reporting of fugitive methane emissions has big implications for industry" https://ieefa.org/resources/gross-under-reporting-fugitive-m...

[4] July 2023: "Australian Fossil Fuels Giants Severely Underestimate Methane Leaks" - "Fugitive — or hidden — methane emissions in the country are likely underestimated by 80% for coal and 90% for oil and gas, a new report from IEEFA say" https://www.bloomberg.com/news/articles/2023-07-04/australia...

[5] March 2022 "Stanford-led study: Methane leaks are far worse than estimates, at least in New Mexico, but there’s hope" https://news.stanford.edu/press-releases/2022/03/24/methane-...