I want to repeat a set of questions I publicly posed to Luke on December 9, few if any of which have been fully answered (despite the statement "Happy to answer any questions").
Hi Luke, Can you provide more information about your launches--locations, flight descriptions, release altitudes and amounts, safety protocols, consultations, permits, funding, etc.? Josh Horton On Thursday, December 29, 2022 at 8:07:48 PM UTC-5 Russell Seitz wrote: > Luke, Make Sunsets has tweeted invoking "trade secrets ' in denying > simple requests to quantify how much helium is needed per > " cooling credit". > This lack of transparency cannot stop anyone , policy analysts included > from running the numbers . > > Dimensional analysis based on handbook and commercially disclosed values > of the physical constants of air, helium and SO2 indicates that you can at > best hope to lift 1.01 Kg per STP cubic meter of 97% pure balloon grade > He. > > Since SO2 vapor's molecular weight makes it over twice as dense as air ( > ~64/29), even if if the dead weigh of the balloon and its telemetry are > completely disregarded it will still take a tonne or more of helium to > loft a tonne of aerosol feedstock to stratospheric elevation. > > As you must be aware, the short supply of helium ( the US strategic > reserve acquired after WWII was largely sold off by 2021) has already > quadrupled its cost., and at present , annual global production is > below100,000 tonnes and recoverable reserves stand at around 30 million > tonnes globally. > > Using NOAA's numbers: > > https://research.noaa.gov/article/ArtMID/587/ArticleID/2756/Simulated-geoengineering-evaluation-cooler-planet-but-with-side-effects > it is clear that your scheme would require lofting of a megatonne or > more of SO2 a year per degree K of cooling: which is not only an order of > magnitude more that present production can bear, but enough to completely > deplete known reserves and resources by 2050. > > Finally, US helium is almost exclusively a byproduct of natural gas > production , and so entails substantial release of methane and other > hydrocarbons that are greenhouse gases more powerful than CO2 > > On Wednesday, December 28, 2022 at 6:09:51 PM UTC-5 [email protected] > wrote: > >> Thanks Andrew, Olivier, Bala, and everyone else for diving in with >> critiques here. I'm a cofounder of Make Sunsets and want to clarify a few >> things: >> >> *Honesty: * >> We have no desire to mislead anyone. If we make a mistake (which we >> will), we'll correct it. >> *Radiative Forcing:* >> I didn't make this "gram offsets a ton" number up. It comes from David >> Keith's research: >> "a gram of aerosol in the stratosphere, delivered perhaps by high-flying >> jets, could offset the warming effect of a ton of carbon dioxide, a factor >> of 1 million to 1." >> <https://keith.seas.harvard.edu/news/whats-right-temperature-earth> >> and, again: "Geoengineering’s leverage is very high—one gram of >> particles in the stratosphere prevents the warming caused by a ton of >> carbon dioxide." >> <https://longnow.org/seminars/02015/feb/17/patient-geoengineering/> >> By stating "offsetting the warming effect of 1 ton of carbon for 1 year," >> I was trying to be more conservative than Professor Keith. I am correcting >> "carbon" to read "carbon dioxide" on the cooling credit description right >> now, and I'm adding a paragraph at the start of the post stating that >> estimates vary, but a leading researcher cites a gram offsetting a ton. >> For the several hundred dollars of cooling credits we've already sold, >> I'll be providing evidence to each purchaser that I've delivered at least 2 >> grams per cooling credit. >> Olivier, or anyone else: I'd be happy to post something by you to our >> blog explaining what you estimate the radiative forcing of 1g so2 released >> at 20km altitude from in or near the tropics will be and why. I will >> include language of your choosing explaining that you in no way endorse >> what we are doing. >> I very much hope to get suggestions from this community on >> instrumentation we should fly to improve the state of the science here. >> Again, I'm happy to do this with disclaimers about how researchers we fly >> things for are not endorsing our efforts. Or even without revealing who the >> researchers are: we'll fly test instruments and provide data, no questions >> asked:) >> *Telemetry: * >> My first 2 flights had no telemetry: in April, this was still in >> self-funded science project territory. After burning some sulfur and >> capturing the resultant gas, I placed this in a balloon. I then added >> helium, underinflating the balloon substantially, and let it go. There is >> technically a slim possibility that neither of these balloons reached the >> stratosphere, as I acknowledged to the Technology Review reporter. I will >> add Spot trackers to my next flights. These cut out at 18km, so I'l be able >> to confirm that I achieve at least this altitude. If (and this is a big if) >> I'm able to recover the balloons, I'll have a lot more data from the flight >> computer >> <https://www.highaltitudescience.com/collections/electronics/products/eagle-flight-computer>. >> >> I will eventually switch to Swarms >> <https://www.sparkfun.com/products/19236?utm_campaign=May%206%2C%202022&utm_medium=email&_hsmi=212205037&_hsenc=p2ANqtz-9EyQOQ6C-9XuSOHa7CggOC8Pf2tEow_Fppo5pXgTHO8-7gV-aHrrYpnPcliws6Ju8j2PBAX3Tkog0oVpwk8XqWX2xo0w&utm_content=212206499&utm_source=hs_email>, >> >> which should let me transmit more data regardless of balloon recovery. >> *Pricing: * >> Bala, you're totally right that this should be priced much lower. We're >> trying to make enough with our early flights to stay in business until we >> get meaningful traction with customers, and we plan to eventually drop >> prices to $1 per ton or less. >> *Reuse: * >> We are not yet reusing balloons, and Andrew is correct that latex UV >> degradation will limit our ability to do so with weather balloons. Given >> that balloon cost is our main expense per gram, even a few uses per balloon >> will dramatically improve the economics here. >> >> I expect to disagree with some of you, but I hope we can do so politely >> and assuming good intentions. >> > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/e5064fb5-6850-4960-a425-e1854ddee44en%40googlegroups.com.
