At least 1.4% of Earth is aluminum. Meteors will have similar composition on average. Aluminum smelting likely vaporizes a much larger volume of material.
> ... the satellites are mostly aluminum; most meteoroids, in contrast, contain less than 1% Al by mass 25 . Thus, depending on the atmospheric residence time of material from reentered satellites, each mega-constellation will produce fine particulates that could greatly exceed natural forms of high-altitude atmospheric aluminum deposition, particularly if the full numbers of envisaged satellites are launched. Anthropogenic deposition of aluminum in the atmosphere has long been proposed in the context of geoengineering as a way to alter Earth’s albedo 26 . These proposals have been scientifically controversial and controlled experiments encountered substantial opposition 27 . Mega-constellations will begin this process as an uncontrolled experiment 28 .
> Concerns are mostly focused on aluminum, the most common component in satellites. If the disintegrated metal ends up as aluminum oxide or hydroxide, it can react with hydrogen chloride — the main reservoir of chlorine in the stratosphere, a hangover from the days of chlorofluorocarbons — to produce aluminum chloride. Hydrogen chloride is a relatively safe repository for chlorine, but aluminum chloride is easily split apart by light, freeing the chlorine to destroy ozone. Metal aerosols could also seed the creation of more polar stratospheric clouds, which catalyze reactions that liberate destructive forms of chlorine. “One can speculate, but without critical laboratory measurements of the chemistry, it’s very hard to know [the effects],” says John Plane, an atmospheric chemist at the University of Leeds. ... “You have to wonder whether [SpaceX] is creating a major problem 30 years from now,” Lionnet says.
It's tough to find figures, but the amount of aluminum lost during smelting not accounted for in dross is as much as half a percent. World smelting capacity is 113 million tons per year. Which maths to as much as 565,000 tons of vaporized aluminum per year.
You're right that it's released into the lower atmosphere, though I'm sure smoke stacks loft that significantly in many cases. And it's difficult for me to believe that a few hundred kg per day, even if all of it ended up in the upper atmosphere, is anything more than a blip in comparison to what lofts up from industry.
The difference would have to be many thousands of times worse for upper atmosphere releases for it to even register.
> though I'm sure smoke stacks loft that significantly in many cases
It must be nice believing that your personal views are always correct.
To know that those geoengineers who want to disperse aluminum oxide to reduce the Earth's albedo clearly don't know how insignificant those aircraft deployed aerosols are compared to the byproducts of aluminum smelting.
To understand that conclusions like 'We find that the population of reentering satellites in 2022 caused a 29.5% increase of aluminum in the atmosphere above the natural level, resulting in around 17 metric tons of aluminum oxides injected into the mesosphere' can be ignored because 17 metric tons should be a blip compared to what lofts up from industry. (Quoting https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.102... )
That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions. (Quoting https://www.viasat.com/content/dam/us-site/corporate/documen... )
> It must be nice believing that your personal views are always correct.
Well that's needlessly confrontational.
> That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions.
Completely baffled as to who said this, and who you're accusing of deliberate obfuscation. The quote certainly wasn't pulled from any of my comments.
And you seem to have assumed a position here which I haven't taken. I have made no statements positive or negative about whether or not aluminum aerosols are harmful. Only that industry dwarfs satellite re-entry. And only after looking up stats.
I hope you're able to have a less angry day! Maybe take a walk?
Follow the URL after "Quoting", on the line immediately following what you quoted. I gave URLs so you could read what actual experts are saying and doing.
> Only that industry dwarfs satellite re-entry.
You have made a hand-wavy gut-feeling conjecture about the amount of human-produced ground sources of aluminum in the upper atmosphere. You have given no stats.
I have linked to several papers and articles by people whose research (scientific and journalistic) say that, yes, the demise of megaconstellation satellites will significantly increase the percentage of aluminum in the upper atmosphere, with potentially negative effects like thinning the ozone layer.
Your belief about ground sources necessarily implies you believe all those researchers must be wrong.
> ... the satellites are mostly aluminum; most meteoroids, in contrast, contain less than 1% Al by mass 25 . Thus, depending on the atmospheric residence time of material from reentered satellites, each mega-constellation will produce fine particulates that could greatly exceed natural forms of high-altitude atmospheric aluminum deposition, particularly if the full numbers of envisaged satellites are launched. Anthropogenic deposition of aluminum in the atmosphere has long been proposed in the context of geoengineering as a way to alter Earth’s albedo 26 . These proposals have been scientifically controversial and controlled experiments encountered substantial opposition 27 . Mega-constellations will begin this process as an uncontrolled experiment 28 .
Or from https://www.science.org/doi/pdf/10.1126/science.adr9689
> Concerns are mostly focused on aluminum, the most common component in satellites. If the disintegrated metal ends up as aluminum oxide or hydroxide, it can react with hydrogen chloride — the main reservoir of chlorine in the stratosphere, a hangover from the days of chlorofluorocarbons — to produce aluminum chloride. Hydrogen chloride is a relatively safe repository for chlorine, but aluminum chloride is easily split apart by light, freeing the chlorine to destroy ozone. Metal aerosols could also seed the creation of more polar stratospheric clouds, which catalyze reactions that liberate destructive forms of chlorine. “One can speculate, but without critical laboratory measurements of the chemistry, it’s very hard to know [the effects],” says John Plane, an atmospheric chemist at the University of Leeds. ... “You have to wonder whether [SpaceX] is creating a major problem 30 years from now,” Lionnet says.