Abstract from the paper in the article:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109280
Large constellations of small satellites will significantly increase the number of objects orbiting the Earth. Satellites burn up at the end of service life during reentry, generating aluminum oxides as the main byproduct. These are known catalysts for chlorine activation that depletes ozone in the stratosphere. We present the first atomic-scale molecular dynamics simulation study to resolve the oxidation process of the satellite’s aluminum structure during mesospheric reentry, and investigate the ozone depletion potential from aluminum oxides. We find that the demise of a typical 250-kg satellite can generate around 30 kg of aluminum oxide nanoparticles, which may endure for decades in the atmosphere. Aluminum oxide compounds generated by the entire population of satellites reentering the atmosphere in 2022 are estimated at around 17 metric tons. Reentry scenarios involving mega-constellations point to over 360 metric tons of aluminum oxide compounds per year, which can lead to significant ozone depletion.
PS: wooden satellites can help mitigate this https://www.nature.com/articles/d41586-024-01456-z
We were in the “we don’t know if we’re causing it” phase for a long time because big oil knew about global warming and deliberately ran disinformation campaigns so they could keep profiteering. Had Exxon done the right thing in the 70s we wouldn’t have this looming crisis.
And now we’re in the “is burning up thousands of satellites bad?” phase of space exploration. I’ll be waiting for spacex to do the right thing.
Don’t get me wrong. I’m not defending corporations here. I’m simply stating the fact that climate change denial wasn’t the case of waiting until it’s “fully confirmed”, it was pretty much confirmed back in the 70s. They even had predictions for the next century on how things will go bad if nothing is done and the last time I checked we were pretty on course with their predictions. When it came to the scientific consensus, it was pretty much “fully confirmed”. It was simply the public opinion where it wasn’t “fully confirmed” because corporations deliberately ran disinformation to make it seem like scientists didn’t know what they were talking about.
But this paper isn’t really confirming anything. The paper itself says that the model does not account for all the factors and to literally quote the paper:
This paper is not presenting a final conclusion, it’s presenting concerns that need further studies. let’s wait for further studies and if there’s scientific consensus about it being an issue I’m all for bringing out the pitchforks. In the mean let’s keep calm and dread over the doom and gloom that is climate change.
It’s highlighting a potential significant risk. Major ozone loss is much worse than lack of internet. The high uncertainty of the paper is easily offset by the harm that would be caused if the paper is correct.
So what are we supposed to do, halt all space flights until we figure this out?
Without further research going into how much damage it’s doing there’s no way to say what our next steps should be. Maybe everything we’re doing is still within acceptable limits? Maybe we need tighter regulation on materials going into space. Maybe some materials need to be outright banned.
The only reasonable thing we can do is study it further. Expecting instant result based on one study that only outlines a potential risk is quite frankly just doomerist behavior.
Well, maybe it’s offset. It’s hard to say whether A > B or B < A when you don’t know the value of either one.
So you’re saying that in the 70s they had predictions about how things will go bad for the next century?
Where are these predictions? It’s been 50 years so at least some of these predictions should be checkable now.
I would feel so much better if I could see some examples of climate science predictions being proven accurate.
It’s pretty public knowledge by now. If you search “ExxonMobil climate prediction” I’m sure you can find a starting point. I recommend finding all the Exxon papers because they’re quite eye opening.