[HN Gopher] Why are there so many methane satellites?
___________________________________________________________________
Why are there so many methane satellites?
Author : bananaphonehome
Score : 69 points
Date : 2024-03-05 16:14 UTC (6 hours ago)
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| codeflo wrote:
| I get that methane has a strong greenhouse effect, and that
| climate models need to account for its concentration to make
| accurate predictions. But in terms of climate activism, isn't
| worrying about methane mostly a red herring?
|
| My understanding is that it only stays in the atmosphere for 12
| years or so. It doesn't accumulate over centuries the way CO2
| does. This means even if we manage to permanently reduce the
| amount of methane in the atmosphere, it would only be a one-time
| effect equivalent to not emitting a certain amount of CO2 once.
| In the long run, the amount of net carbon added to or removed
| from the carbon cycle, for example from fossil reservoirs, is the
| only thing that really matters.
| piva00 wrote:
| It reacts with ozone to decompose into carbon dioxide, so
| methane not only has a much higher short-lived effect but later
| turns into CO2.
| etrautmann wrote:
| That's exactly why it's also worth targeting. Its short
| residence time means that addressing methane emissions could
| make a meaningful impact. It's not zero sum - we should address
| the low hanging fruit of methane emissions while also
| decarbonizing.
| toomuchtodo wrote:
| You can also repurpose oil and gas industry people and
| equipment as part of this work (the Inflation Reduction Act
| appropriated funds for this). This provides a graceful
| rolloff for these folks and the industry as oil for energy is
| sunset.
|
| https://www.doi.gov/pressreleases/through-president-
| bidens-b...
|
| https://www.energy.gov/fecm/funding-notice-ira-mitigating-
| em...
|
| https://www.propublica.org/article/the-rising-cost-of-the-
| oi...
|
| (US centric, but the model transfers)
| bilsbie wrote:
| Wouldn't that just embolden folks to emit more co2?
| burkaman wrote:
| It might if companies sell carbon credits based on methane
| reduction, but that's an argument against the credits not
| against the actual mitigation action.
| angiosperm wrote:
| There is a project to get transcontinental ships to add
| emitters of FeCl3 to their exhaust stacks, to catalyze
| oxidation of methane. It seems to be getting enthusiastic
| uptake from shipowners for reasons unknown to me. 10,000
| ships emitting 100kg a day would be enough to bring
| atmospheric methane in line.
|
| (Fe seeded to the ocean surface is negligible. This is not a
| thing to trigger algae production.)
|
| https://en.wikipedia.org/wiki/Atmospheric_methane_removal
| trompetenaccoun wrote:
| That's a misunderstanding. The methane stays in the atmosphere
| a few years until it reacts with oxygen to CO2. So first you
| have the multiple times worse effect of CH4 and then you're
| left with CO2, which is still a greenhouse gas. You're left
| with CO2 either way, even when you burn the methane. That's why
| it's so bad. And that's why actually when companies or
| politicians tell you about "clean" gas, it's very misleading.
| There is significant leakage in production, transport and
| storage, before the gas even reaches a consumer.
| codeflo wrote:
| Sure, but the question is still whether that carbon came from
| a fossil source or was part of the cycle to begin with.
|
| Let's say a cow eats grass, produces methane, the methane
| gets converted into CO2, the grass grows back. No net
| increase in CO2.
|
| If, on the other hand, the methane came from natural gas, you
| have permanently added carbon to the cycle.
| staunton wrote:
| The "short-term" effect on warming is quite severe and very
| relevant. Also, while carbon atoms are conserved, methane
| is not. You can make a lot of methane from biomass without
| needing to absorb methane to produce the biomass.
| burkaman wrote:
| > No net increase in CO2.
|
| 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.
| wolverine876 wrote:
| > the question is still whether that carbon came from a
| fossil source or was part of the cycle to begin with.
|
| I don't think that matters anymore. At some point, we
| wanted to reduce atmospheric CO2 to a tolerable level and
| an obvious approach was to not add to natural emissions.
|
| Now we just need to reduce CO2 in the atmosphere. It
| doesn't do different things based on its source. If we can
| reduce it by cutting gas production or by cutting some
| natural source, we should do it.
| gopher_space wrote:
| In your thought experiment the number of extant cows is a
| variable determined by human behavior as opposed to
| inherent regulation. There might be historical population
| numbers from specific regions where carbon was in
| equilibrium but that's certainly not where we're at today
| nor is it a goal of ours.
|
| I think we're only able see some carbon sources as "outside
| the cycle" due to our infinitesimal lifespans.
| metaphor wrote:
| > _So first you have the multiple times worse effect of CH4
| and then you 're left with CO2, which is still a greenhouse
| gas._
|
| In case anyone else was wondering, the EPA[1] puts a layman
| figure on that notional multiple:
|
| >> _Methane 's lifetime in the atmosphere is much shorter
| than carbon dioxide (CO2), but CH4 is more efficient at
| trapping radiation than CO2. Pound for pound, the comparative
| impact of CH4 is 28 times greater than CO2 over a 100-year
| period._
|
| [1] https://www.epa.gov/ghgemissions/overview-greenhouse-
| gases#m...
| codeflo wrote:
| But note that at the end of that century, the CO2 is still
| there and will continue to heat the atmosphere
| indefinitely. We really need to stop adding carbon to the
| cycle; optimizing the form of that carbon can only ever be
| a secondary goal.
| daedrdev wrote:
| I think the idea is even in those 12 years, it's way more
| damaging than CO2 will be. Over 100 years, it is 28 times more
| damaging than C02, despite not being in the atmosphere for most
| of that time.
|
| Plus doesn't it just break down into CO2 anyway, meaning that
| methane does its direct damage, plus creates more CO2.
| codeflo wrote:
| It only creates "more CO2" if the carbon atom wasn't part of
| the carbon cycle to begin with. That's the case for natural
| gas, but not for biological sources.
| Scarblac wrote:
| The half life is 12 years.
|
| So after 24 there's still a quarter, after 36 still an eighth,
| etc. It's worse than CO2 for a very long time, and then it is
| CO2.
| codeflo wrote:
| I just looked it up to be sure. It seems like the mean
| lifetime is 12 years, which is the figure one uses for
| calculations. The half life is shorter.
| seadan83 wrote:
| I think this is like saying "my car payments are $1000 per
| month for the next 10 years, and my rent is $30 per month for
| the next 80 years. For my financial health, why am I worried
| about the car payment when I will be paying rent for the rest
| of my life and the car payments will be over relatively soon?"
| The answer to that is the situation might not work out well..
| If you have a total lifetime budget of $150k, then those car
| payments are devastating and you would be bankrupt before those
| 80 years are over.
|
| A kicker, who is to say that methane emissions are one time -
| and are not themselves increasing and also ongoing?
|
| The analogy is not quite exact, since the "rent payment" is
| more akin to be on the order of 200 years or so (and not just
| the one human lifetime), but hopefully it makes the point.
|
| Last, my understanding of the climate science is that we are
| very worried about getting through even the next 100 years. To
| explain, there is a window of time that is almost closed where
| drastic action can arrest further drastic rates of change in
| climate (by drastic rates, I'm speaking to 1 to 2 degrees C of
| warming within that time). It is important therefore we get a
| handle of this problem sooner rather than later (compare us
| (humans) "fixing" the methane problem 5 years from now compared
| to 30 years from now). Also keep in mind there are feedback
| loops that would be irreversible once triggered.
| toss1 wrote:
| The TFA answers it's question
|
| >>"So why do we keep launching more?"
|
| >>"Despite the small army of probes in orbit, and an increasingly
| large fleet of methane-detecting planes and drones closer to the
| ground, our ability to identify where methane is leaking into the
| atmosphere is still far too limited. "
|
| And a lot of nice detail is provided about particular satellite
| programs
| cabirum wrote:
| Because these are either spy sats or even weapons in space
| disguised as "methane detectors".
| alwa wrote:
| "Many" seems to mean only a dozen-odd. Which seems like an
| awfully small number to image the entire earth at meaningful
| levels of resolution or frequency.
|
| Which also seems to be the article's lesson.
|
| FWIW, it looks like Starlink alone is up to 5,942 satellites in
| orbit [0] these days
|
| [0] https://planet4589.org/space/con/star/stats.html
| llbeansandrice wrote:
| > it looks like Starlink alone is up to 5,942 satellites in
| orbit [0] these days
|
| Starlink operates by far the largest constellation of
| satellites. Definitely the largest commercial constellation.
| That's like saying Google "just" serves ~8.5bn search
| queries/day. I might be mistaking your implication tho.
| dylan604 wrote:
| the field of view from LEO (for Starlink) is so much smaller
| than from GEO. I'm not sure what the orbit is for the methane
| satellites, but the number of satellites alone isn't the only
| factor.
| angiosperm wrote:
| If SpaceX cared, the Starlink fleet (both satellites and
| ground stations) could be the biggest, most sensitive radio
| telescope in the world, without compromising its usefulness
| as a network. It points in all directions at the same time.
| With such sensitivity, a very short "exposure" time is
| plenty.
|
| Each node records a few cycles of analog waveform at a
| certain atomic-clock time determined by its position, and
| forwards that to a common collection point to correlate with
| the others.
| ianburrell wrote:
| The Starlink satellite antennas all point at the Earth. The
| antennas are also small compared to radio telescopes. They
| also listen to specific frequencies. They would make the
| best radio telescope for detecting Starlink customers.
|
| 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.
| cmyr wrote:
| If you're going to post quite sensationalist speculation please
| at least provide some attempt at a source or rationale. It
| doesn't really pass the sniff test that any goverment would
| bother with this banal subterfuge when they are more than
| capable of putting secret payloads into orbit, and have done so
| many times[1].
|
| e.g. this, just the first relevant thing I could find
| https://spaceflightnow.com/2021/04/26/spy-satellite-successf...
| iraqmtpizza wrote:
| Secret payloads which are impossible to track via radar or
| optically either from the ground or via other satellites?
| Really? Tell me more.
| wongarsu wrote:
| There was Zuma, the classified satellite that officially
| failed to separate from the payload adapter and burned up
| in the atmosphere but was widely speculated to be a
| successful test of stealth satellite technology, with the
| satellite successfully reaching orbit and going dark. A lot
| of talk about us knowing very little, but everyone loved to
| show off this graphic from a stealth satellite patent [1].
| Of course if the NRO does a good job and the technology
| works we will never know that it does.
|
| 1: https://pbs.twimg.com/media/DTW_zc_W0AEH3Un?format=jpg&n
| ame=...
| iraqmtpizza wrote:
| Widely speculated by advanced radar owners and high-power
| telecope owners? Can you give me a few names?
| wolverine876 wrote:
| Why would they need a cover story? They launch spy and other
| secret satellites all the time, openly announcing when many are
| launched.
| jandrese wrote:
| The post goes into details about coverage vs. resolution and
| shows you the data from the satellites and your first thought
| is that it's all a big lie/coverup?
| stratigos wrote:
| I would guess for the same reason the government consistently
| buys $1000 hammers and $5000 toilet seats - to mask some military
| operation theyd rather not publicly report on.
| Alex3917 wrote:
| FWIW this video has a good explanation of why this new satellite
| was launched:
|
| https://www.youtube.com/watch?v=rhWcFShBAFE
|
| And this New Yorker article has a much more detailed explanation:
|
| https://www.newyorker.com/news/annals-of-climate-action/a-se...
| jauntywundrkind wrote:
| With permafrost thawing and arctic warming releasing methane
| clathrates, methane has been on my mind for a while. I wonder if
| these satellites will also be useful in detecting dispersed wide-
| area releases like these?
|
| The current publicly available tools like
| https://methane.jpl.nasa.gov/ seem to focus on showing methane
| plumes. Which is good & something we are better positioned to do
| something about. But I wonder if these tools might help us see
| both impact of the already underway colossally fast climate
| change we are undergoing, which will only speed up all the faster
| as these trapped sources make their way out to the atmosphere.
| mturmon wrote:
| The OP touches on the question of "why the focus on plumes and
| not on tundra or wetlands", and has a quote from Andrew Thorpe
| hinting at an answer.
|
| >> "These types of emissions are really, really important and
| very poorly understood," [Andrew] said. "So I think there's a
| heck of a lot of potential to work towards the sectors that
| have been really hard to do with current technologies."
|
| I try to keep touch with work in this area. I think it's a
| combination of SNR and resolution/coverage. The CH4 from a gas
| leak is very concentrated and so it puts a strong imprint on
| the spectrum of light passing through it. The natural sources
| are more diffuse and have less contrast with the surroundings.
|
| (For earlier airborne experiments, the JPL team [which included
| Andrew] was using a simple matched filter aligned with the
| methane absorption bands - now they may be using something more
| complex. This was able to run on a computer on the airplane
| holding the sensor as it flew over regions of interest.)
|
| Anyway, for sources with a lower CH4 concentration, there will
| be a much weaker spectral signature. It will be hard to
| distinguish from other influencers like water, aerosols/dust,
| etc., or from instrumental effects that may be correlated with
| location. (E.g., "sometimes high water concentration has
| spectral effects that appear as high CH4 concentration, so our
| CH4 values over moist areas are sometimes too high.")
|
| You can improve the effective SNR by accumulating results over
| a larger area (of space or time). As noted in OP, the ability
| to get large-area, frequent coverage is quite new.
|
| And also, CH4 moves, so to combine measurements taken at
| different times, you need to account for transport. This is the
| difference between measuring "concentration" (a quantity we're
| more-or-less directly measuring) and "flux" (an emission rate
| over time, which we don't get to measure directly).
|
| As noted in OP, the plumes were a low-hanging fruit (or as they
| say, a fruit lying on the ground. ;-)
| jandrese wrote:
| There's also the aspect of "Ok, you have detected methane
| release from melting permafrost, what are you going to do about
| it?" Capping a leaking oilhead is fairly straightforward. What
| are you going to do about arctic warming other than the
| generalized fight against global warming that these projects
| are already doing?
| FranOntanaya wrote:
| I'd think it's also useful for economists and investors trying to
| factor activity from other countries without any middle-people
| obfuscating the data. That kind of information will always find
| funding.
| jessriedel wrote:
| Putting aside the climate aspects and just concentrating on
| companies that are trying to identify methane leaks: If I have a
| device that can accurately see methane leaks, I am very surprised
| it's really more economical to put them on satellites than to
| operate them locally. Yes, I get that you can have one device in
| orbit that can do the job for multiple companies, but satellites
| are just fantastically expensive. Unlike photography, where the
| alternative is to use an also-expensive airplane, why can't
| companies just survey from the ground?
| falcolas wrote:
| It's probably simply efficiency. You can check an entire
| pipeline faster from space than from the air, and from the air
| vs. the ground. Those efficiencies save a fair bit of money,
| and probably also lead to earlier detection.
|
| And while they are expensive, we're talking about low single-
| digit millions of dollars for a satellite which has a lifespan
| of 5+ years. Relatively inexpensive for the companies who would
| want to use them.
| dannyz wrote:
| The short answer is to measure methane you rely on methane
| absorption features. To do that you need to be looking at a
| source through the methane plume, from a satellite this source
| is the ground. From a ground instrument you can use the sun as
| a source, but it limits the times of day/direction/location you
| can measure from.
| photochemsyn wrote:
| Ground-based sampling has different capabilities, e.g. these
| days you can mount a small mass spectrometer (see the ones
| going to Mars, the Moon) or related devices on a drone and get
| data about a much wider range of particulates and compounds.
| e.g.
|
| "VOC Sampler on a Drone Assisting in Tracing the Potential
| Sources by a Dispersion Model - Case Study of Industrial
| Emissions" (2023)
|
| https://aaqr.org/articles/aaqr-23-07-tn-0169
|
| > "Two plants which manufacture petrochemical products at an
| industrial complex in Kaohsiung City, southern Taiwan, were
| applied as the targets for VOCs sampling and further
| qualitative and quantitative analysis in the laboratory.
| Aromatic hydrocarbons, including toluene of 433 ppb,
| ethylbenzene and xylenes of 100-200 ppb and phenol of 111 ppb
| were identified."
|
| US EPA also has a similar program.
| perrygeo wrote:
| > satellites are just fantasically expensive
|
| Are they? A CubeSat can be launched for less than $100k, and
| their payload can contain off-the-shelf consumer hardware.
| That's what some upper-middle class families pay for an extra
| car. I think you're overestimating the cost of satellites.
|
| At the same time, you're underestimating the challenges of
| operating a ground sensor network. How would identify which
| sites to survey from the ground without a broader search? Would
| the oil industry get to regulate itself? What about temporal
| variability or detecting flares? How would you detect new leaks
| and add new sensors? What about large-scale natural leaks that
| spread over many kms in inaccessible terrain?
|
| Even assuming you could pinpoint the location of every active
| methane source ahead of time, how would you get a sensor there?
| How would you secure access for installation and maintenance?
| How would you ensure connectivity? How would you monitor in
| areas controlled by hostile governments?
|
| Each of the hundreds of thousands of sites has its own
| logistical challenges which explode the cost. And because you
| need to keep the sensor network up to date, it's a constant
| operational battle, not a one time expense. Compare that to a
| satellite: the one-shot launch, then lower cost, lower
| operations, and superior temporal detection abilities and
| global coverage - not hard to understand why satellites are
| preferred.
| downWidOutaFite wrote:
| I mostly agree but the $100k is only launch cost, it doesn't
| include the engineering and manufacturing of the satellite or
| the ongoing operational costs.
| 0cf8612b2e1e wrote:
| Well funded universities are putting up cubesats. I cannot
| imagine the operational costs are outside the scope of a
| serious organization.
| gopher_space wrote:
| $100k would only hire a single employee, it wouldn't even
| cover getting them into the field let alone setting up and
| maintaining infrastructure over the course of a year.
|
| It's possible to reduce this number by taking advantages of
| labor conditions and goodwill, but that turns out to be a
| ton of legwork if you want a reliable team in the area year
| after year.
|
| For example, in an anthro field school you might source
| local labor by identifying people who want to learn about
| their ancestors, and you'll expect a lot of community
| outreach and Q&A sessions around what you're studying.
|
| You could attempt a similar approach for studying methane
| but I'd personally expect the Q&A sessions to include a
| heavy undertone of "convince me we shouldn't just kill the
| people involved", and all of my arguments against would be
| from the perspective of a system they don't really give a
| shit about. I'd certainly never put myself in that
| position.
| Denvercoder9 wrote:
| > satellites are just fantastically expensive
|
| This has become less and less the case over the last decade or
| so. There are more or less mass-produced satellite buses now,
| and a SpaceX rideshare puts 150kg into orbit for less than a
| million. If you go small, you can probably procure, launch and
| operate a satellite for less than $1000 per day of usage.
| chris_va wrote:
| (disclaimer I work on climate/methane mapping)
|
| Companies do survey from the ground, and for large facilities
| there is often permanent monitoring.
|
| Detecting methane from the ground still requires an expensive
| instrument, and it covers a very tiny area.
|
| Having said that, a lot of methane leaks are from abandoned
| well heads, and in many places there just are no economic
| incentives to care about it.
|
| Anyway, satellites are not cheap from a capex standpoint, but
| they are surprisingly cheap in terms of $/m^2. A camera moving
| over the earth at 7km/s mapping a 200km swath can cover a
| million square km for O($1000). Getting a team with expensive
| equipment into the field for a day on one site could easily be
| more than that.
| vineyardmike wrote:
| I used to work on this at a methane monitoring shop. Others
| have good points.
|
| 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.
| diracs_stache wrote:
| In calibrating satellites getting folks like you to go out
| with sensors on the ground to send back well vetted data is
| an expensive and limiting factor. Much cheaper (and often
| preferred) to do as much as possible from space and do smart
| ground processing/data analysis to build confidence.
| seadan83 wrote:
| > why can't companies just survey from the ground?
|
| 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-...
| OtherShrezzing wrote:
| Companies and countries tend not to report catastrophic methane
| leaks (or really any contamination event) unless they're caught
| in the act. It's absolutely staggering the rate at which
| methane leaks are identified now that satellite data is being
| analysed and published.
|
| It'd be much more efficient all round for firms & countries to
| just test locally & report their methane leaks, but they can't
| be trusted to do so.
| jasonlaramburu wrote:
| Ground-based sensors historically undercount methane emissions
| in 3rd party trials. They have a limited FOV which makes it
| hard to accurately measure a plume of gas, particularly when
| the wind blows. I suppose you could create a Dyson sphere of
| fixed sensors around an O&G asset, but that quickly becomes
| more expensive than a space based sensor.
|
| Because these leaks can occur spontaneously, you really want
| real-time, continuous monitoring of a wide area with high
| resolution. Aerial sensors are impractical for this purpose.
| Only a large constellation of satellites can offer this.
| photochemsyn wrote:
| How these satellites work (full text):
|
| "Mapping methane point emissions with the PRISMA spaceborne
| imaging spectrometer" (2021)
|
| https://www.sciencedirect.com/science/article/abs/pii/S00344...
|
| > "The retrieval of methane from space measurements typically
| relies on spectrally-resolved measurements of solar radiation
| reflected by the Earth's surface in the shortwave infrared (SWIR)
| part of the spectrum (~1600-2500 nm). Methane presents two
| absorption bands in this region, a weaker one around 1700 nm and
| a stronger one around 2300 nm. Carbon dioxide, nitrous oxide and
| especially water vapor also present optical activity in the SWIR
| (see Fig. 1)"
| omgJustTest wrote:
| Methane detection from space![1] will aid in the detection of
| greenhouse gas emissions from abandoned well-heads, oil-fields,
| landfills and other large environmental polluters contributing to
| climate change. The IEA[3] has attributed nearly 30% of global
| temperature rise to methane, so the detection of the sources is
| becoming a critical factor in mitigating direct and indrect
| impacts of climate change. The sensors aboard the MethaneSAT, as
| well as other deployed capabilities, are largely based IR
| detections with tunable bandgap materials like HgCdTe[2] arrays.
| HgCdTe allows for the detection of non-ionizing IR via bandgap
| tuning of the direct semiconductor CdTe. IR bands, and thus
| chemical specific detections, can be selected based on the Hg
| doping. Similar technologies in the James Webb NIRCam enable
| detection of red-shifted gamma rays that are now heat photons.
|
| [1]https://www.nature.com/articles/d41586-024-00600-z
|
| [2]https://www.methanesat.org/satellite/
|
| [3]https://www.iea.org/reports/global-methane-
| tracker-2022/meth...
| jimnotgym wrote:
| Imagine the carbon released by putting all the satellites up
| there!
| jjcm wrote:
| I was curious on this so did some quick searching around.
|
| Average satellite launch releases 57 tons of Co2 [1]
|
| 2.75 million unplugged wells in the US that output "6.6m tons
| of Co2 worth of methane" [2], or put in another way each well
| puts out 2.4T of Co2e each per year.
|
| With these numbers each sat would have to prevent 23.75 years
| worth of a well being uncapped to recoup the cost of launch
| (so would have to close one well for 23.75 years, or 24 wells
| for a little less than a year).
|
| [1] https://www.linkedin.com/pulse/carbon-footprint-
| satellite-to...
|
| [2] https://carboncontainmentlab.org/projects/plugging-
| abandoned....
|
| (someone more informed feel free to correct any of these
| numbers, I am not an expert)
| Timshel wrote:
| > The biggest event was a leak of 427 tonnes an hour in
| August, near Turkmenistan's Caspian coast and a major
| pipeline.
|
| From this Guardian article: https://www.theguardian.com/env
| ironment/2023/mar/06/revealed...
| nonameiguess wrote:
| Your link says around 57 tons for a "typical" payload
| launched by the ESA using an Ariane 6 rocket and <15 tons
| for a payload that launches from a reusable platform. The
| parent article says these are launching using SpaceX
| rockets, which are reusable, so presumably their footprint
| is lower than an ESA satellite. They're also extremely
| small satellites and not exactly typical payloads. Possibly
| they can even fit multiple satellites on a single launch.
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