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
There is a line somewhere I think. Like people weren’t 100% sure the atomic bomb won’t ignite the atmosphere (it’s only very unlikely), but they still tested it. Similarly the probability of creating micro blackholes at LHC is not zero either, yet they still ran it.
If we have to make sure everything is 100% safe before we can do anything, we will be stuck with the status quo.
We will die of starvation because nothing is 100% safe, so waiting until we find that level of safety means we just won’t do anything.