Comment by AncientTree | Hacker News Reader

Comment by AncientTree | Hacker News Reader

My biggest concern about CO2 is the cognitive impact it has on humans - at levels 800ppm and higher, mental performance is impacted. It will take a while for the atmosphere to reach this level (hopefully it never does), but it is common inside houses and offices. As atmospheric CO2 rises, it becomes more difficult to ventilate buildings, and human mental performance degrades.

In terms of geoengineering, it seems like these two are our best bets:

https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio... to prevent runaway warming. As a side effect, the dispersed sunlight helps plant growth. Solar power generation is negatively impacted though.

https://en.wikipedia.org/wiki/Iron_fertilization to sequester CO2. As a side effect, marine life and fish stocks would be boosted by the greater plankton food supply.

In any case it seems absolutely bonkers that we are still selling fossil-fueled-vehicles and building coal power plants when we clearly have the technology and capability to replace both of them.

The amazing thing about stratospheric aerosol injection is that fully negating the effect of global warming would cost less than $5 billion per year.[1] That's less than 0.01% of world GDP. That's cheap enough for a single major country to unilaterally take on itself.

In contrast going fully carbon neutral would cost the economy at least 100 times that amount. And even then it would still result in some amount of warming between 1.5-3 C. Plus require multilateral commitment from nearly every country.

To me the calculus seems to strongly favor forgetting about carbon mitigation completely. Instead just focusing on immediately starting aerosol injections. The tech already exists and is ready to be deployed. Starting sooner will give us time to get better at using it, and discover any potential pitfalls.

Then in 100 or 200 years, we can switch over to more advanced geoengineering that fully and permanently scrubs carbon out of the atmosphere. Aerosol injection would act as a stopgap measure until the carbon-scrubbing is cost-effective.

[1] https://iopscience.iop.org/article/10.1088/1748-9326/aae98d

Have you got a reference for the 800ppm bit? Not being provocative - it'd be genuinely useful to me.

https://en.wikipedia.org/wiki/Carbon_dioxide#Below_1%

There are multiple studies on the issue, and another user linked to Wikipedia.

I'd personally recommend buying a CO2 monitor: https://www.aliexpress.com/item/32887534678.html?spm=a2g0o.p...

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