> if you read any accounts by astronauts, there’s a profound effect on people that get a chance to look back at earth, and see how it’s actually not infinite
Still no astronaut says that they don't want to go back because it contributes to destroying the planet, do they?
Don't get me wrong: I would probably throw my principles out the window if I got to become an astronaut. But I don't think we can say that going in space makes you a big environmental activist.
The carbon footprint of an astronaut going into space on eg a Falcon 9 is on the order of that of a couple average American families for a year. It's not a huge impact compared to how much they advance our understanding of how to live in space (back of the envelope, ~150 tons of kerosene yielding ~500 tons of CO2, 50 tons for the average American family for a year). I haven't run the numbers on Starship, but my impression is that it'll be significantly more efficient.
> The carbon footprint of an astronaut going into space on eg a Falcon 9 is on the order of that of a couple average American families for a year.
You certainly mean the direct carbon footprint, right? Not counting what was involved in building the rocket, importing the material, test launches while developing the technology, etc?
> It's not a huge impact compared to how much they advance our understanding of how to live in space
Not sure I get that comparison. So you say "it's okay to contribute destroying life conditions on Earth in this case, given how much it helps us understand how to make people survive around Earth"? We can't move the Earth population to live in orbit once surviving on the ground is impossible, so it's a bit like saying "the carbon footprint of burning tires is not huge compared to how practical it is as a way to get rid of tires", IMO.
We won't, as a species, go live in orbit, we won't go live on the Moon, and we won't go live on March. And we quite certainly will not ever reach the next star (which is what, 4 light-years away?). We don't need to understand how to live in space in order to survive on Earth. And right now we are destroying Earth. We need to first learn how to survive on Earth, and then maybe we can consider playing with human spaceflights again.
> I haven't run the numbers on Starship, but my impression is that it'll be significantly more efficient.
Again, you're missing all the indirect impact, and then all the rebound effects. Every success of SpaceX gets us into a world where the space business (because it is now a business) emits more CO2. I don't know why people don't get the memo, but right now our survival depends on reducing our CO2 emissions, not increasing them.
I've gotten the memo, thanks, I've devoted a good amount of time to this stuff, and yes, some things are useful enough that they're worth emitting their relatively insignificant amounts of CO2 for. Obviously, it's the wrong direction on CO2, but we don't have an alternative for lifting stuff into space, yet. And even if they got to 10,000 Falcon 9 launches per year (they're at ~80, so >100x), it would add something like 0.02% of our current global emissions.
wrt direct vs. indirect emissions, rockets are incredibly thin cans full of fuel that immediately gets burnt. The direct emissions will almost certainly dominate the embodied carbon from manufacturing, especially when they're launched >10 times. Once you start including the infrastructure, it's less clear, but it's a close-enough estimate for setting the context in an internet comment. Is the value we get from an astronaut doing work in space worth the carbon footprint of a few American families for a year? I think so, I get the sense that you don't agree. That's fine.
> Is the value we get from an astronaut doing work in space worth the carbon footprint of a few American families for a year? I think so, I get the sense that you don't agree. That's fine.
You make it sound like we get a lot of value from astronauts surviving in space, and that the CO2 footprint of the space business is almost nothing.
I disagree with both. They don't really make any useful work (that could not be done by robots) other than surviving there, and the carbon footprint of the space business is going to grow much bigger (if those companies are successful) than what you seem to believe.
> it's less clear, but it's a close-enough estimate for setting the context in an internet comment
Still no astronaut says that they don't want to go back because it contributes to destroying the planet, do they?
Don't get me wrong: I would probably throw my principles out the window if I got to become an astronaut. But I don't think we can say that going in space makes you a big environmental activist.