Luke: In the stratospheric balloon releases you have so far described, how many grams of helium are required to loft one gram of SO2?
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/4cccd605-41cb-4c84-a5b8-4a4c6b6c027an%40googlegroups.com.
