There are those who argue it could hurt Earth a lot less, to mine metals and rare earth elements off-planet.
There are two large caveats, says Ian Lange, professor, economics and business, and deputy director of Critical Materials Innovation Hub, Colorado School of Mines — and co-author of a study published in PNAS that reported complementary findings. This metal is so rare on Earth, and requires so many tonnes of rock to be processed in order to find it, that mining a platinum-rich asteroid could end up having a far lower carbon footprint. The first caveat is that the CO2eq estimates do not yet take into account the exploratory work needed to make such asteroid mining possible. “The launches do affect the greenhouse gas cycle. There is hope for different kinds of fuels, but we’re not there yet. We need to better understand how the environmental trade-offs work. “But space is not ‘the other’. Earth sits in it too. We have to account for that. Her concerns are two-fold as well. An increase in launches and orbital traffic puts more space junk in Low Earth Orbit (LEO), raising the risk of collisions and cascading debris. This could make LEO more hazardous to use, just as we start to use it more (for the laboratories, hotels and tourist centres already planned here). Meanwhile, we don’t know enough about asteroids to know what to look for in an environmental impact assessment. MINE THE GAP Both Lange and de Zwart point to the escalating nature of the conversation around such mining operations. There have been discussions, for instance, over how much of what’s out there should be protected from human activity. This tripwire would be triggered when one eighth of the Solar System’s resources are close to being exploited,” the authors noted. There are those who argue that this is a reasonable risk to take; that we need to do what we can to plan for a future that may not be confined to a struggling Earth. There are others who point out that a struggling Earth needs our attention, and cannot take too many more of these operations. The mistake we make, as always, is in thinking of it as Earth that struggles.
A study by researchers at the University of Paris-Saclay, presented at the 69th International Astronautical Congress in 2018, used platinum as an example. The carbon cost could drop to about 150 kg of CO2eq per kg of platinum obtained (including rocket launch and re-entry), against roughly 40,000 kg of CO2eq for every kg produced on Earth using existing mining practices, they estimated. The second: We know very little about what it might take to realistically conduct such mining operations, or what changes an asteroid might undergo as a result of them.
Put simply, we don’t really know how it could all add up, says Lange. GROUND CONTROL Instead, we seem intent on “colonisation”, as if colonisation has ever been a good thing in the long-term, says Melissa de Zwart, professor of space law and governance at the Andy Thomas Centre for Space Resources at Adelaide University in Australia. “There is this idea that by mining in space, our problems are going to go away,” she adds. Mining them could alter them in unpredictable ways and more research is needed, de Zwart says. In 2019, astrophysicist Martin Elvis from the Center of Astrophysics, Harvard & Smithsonian, and philosopher Tony Milligan from King’s College London, in a paper published in Acta Astronautica, proposed a striking “one-eighth principle”. Humanity, they said, should exploit no more than one-eighth of the solar system’s usable resources, leaving the remaining seven-eighths as “space wilderness”. “Our limited ability to see ahead until such processes are far advanced, suggests that we should set ourselves a “tripwire” that gives us at least 3 doubling times as leeway.
We are among the most fragile things on it. The struggle is ours. The answers will affect us, are affecting us, as our planet continues to turn, the way it has for billions of years.
