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Direct air capture is really about the least realistic of popular geoengineering proposals. The atmosphere is huge. We didn't get into this situation overnight
by mjhay 2y ago
Direct air capture is really about the least realistic of popular geoengineering proposals. The atmosphere is huge. We didn't get into this situation overnight - it took almost two centuries and oodles of factories, vehicles, concrete plants, etc. It's vastly cheaper just not to output more CO2 in the first place. Thermodynamic constraints mean that tremendous amounts of energy are required to do DAC in the first place, not to mention the knock-on biosphere effects of the production required to build that hitherto-unseen scale of capability.
We can't magic-tech our way out of this situation. It will take huge effort, and more importantly, sacrifice of the unthinking low-value abundance we have. Nuclear power is hard, but it is still much more realistic than unproven wundertech like DAC.
- thehappypm 2y agoYep. We basically doubled the amount of CO2 in the atmosphere. If we had a machine that could take some volume of air and scrub all the C02 out, we’d need to pass half of the atmosphere through it to cut the CO2 in half.
- ElevenLathe 2y agoI think the point is that even if we can scale up DAC to work, we need some carbon-free source of energy to power it. Fixing the atmosphere essentially means we need enough non-emitting energy to run civilization since 1850 in reverse, and preferably much faster than 1x.