3 ms·

Why not store the CO2 in limestone and build ultra-durable buildings with it (eg, the Egyptian/Mayan pyramids) instead?

• philipkglass 8y ago
  Human activities released nearly 37 billion tons of CO2 in 2017. That would yield about 84 billion tons of limestone if it were captured as pure calcium carbonate. Estimated mass of Mt. Everest: 450 billion tons (I went with the answer from the person who used terrain contour data): https://www.quora.com/What-would-the-estimated-weight-of-Mount-Everest-be https://www.quora.com/What-would-the-estimated-weight-of-Mou... It admittedly would be pretty awesome, if impractical, to build two Mount Everests per decade from CO2-captured-as-limestone. Building things out of CO2 captured as minerals, building things out of CO2 captured as wood: they're fine ideas, but they are also grossly inadequate to offset current emission rates. That's why every plan for curbing AGW starts with deep emissions cuts. It's a lot easier to not emit CO2 in the first place than to capture CO2 that has already been emitted. Plans for negative emissions are still necessary but they can't deal with tens of billions of tons of CO2 per year.
  • nonbel 8y ago
    >"Human activities released nearly 37 billion tons of CO2 in 2017. That would yield about 84 billion tons of limestone if it were captured as pure calcium carbonate." Assuming there is a goal is zero net CO2 added to the atmosphere, that 37 Gt emitted is an upper bound of what needs to be sequestered. Apparently the total amount of construction material used is around 50 Gt per year. https://www.concreteconstruction.net/business/global-demand-for-construction-aggregates-to-exceed-48-billion-metric-tons-in-2015_o https://www.concreteconstruction.net/business/global-demand-... So, that doesn't seem unreasonable to me.