71–80 of 120 posts
I wrote up a summary of the big picture emissions here last year: https://climate.davis-hansson.com/p/big-picture-2020/
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While nuclear has different pollution than fossil fuels, one can hardly call it green with the everlasting poison it produces.
Green is an unhelpful umbrella term IMO. We need to be specific. Even "low carbon" is vague and prone to abuse.
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We could avoid this number by investing in soil preservation, nitrogen fixing plants, reduce meat consumption, even in concepts like humanure.
None of these would produce as much food per area and time. Reducing total calories required by eating less meat is a different argument.
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At least the poison is very concentrated and easy to store. CO2 in the atmosphere is "forever" too, and much harder to deal with.
Not really, the most abundant life forms on earth consume CO2 to grow. Of course not at the rate we would like (especially with current coverage and that we’re still freeing more carbon daily by chopping down more forests).
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With very-high-temperature reactors (one of potential paths for Generation IV reactors) you can produce hydrogen using reactor heat directly, bypassing the electricity conversion step, thus significantly improving efficiency of the process. And with sufficiently cheap hydrogen you would not be able to produce fertilizers, but also steel, another dominant CO2 source.
Oh I absolutely agree that nuclear is a brilliant choice for hydrogen production. And presumably it would allow nuclear to adjust electricity output whilst maintaining high utilisation and profitability. But still I think there is a mistake in assuming that everything needs to be tightly coupled. The benefit of an electricity grid and storable fuels is that you have flexibility.
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Is then hydrogen liquefied? I remember reading somewhere that hydrogen requires pretty heavy/thick containers for storage. Does it need to be kept at low temperatures?
The Haber-Bosch process used in ammonia production is done at high temperatures (400-500 °C), so you can use "hot" hydrogen to power it (i.e. to heat input nitrogen) and maybe even extract some of leftover energy in produced ammonia heat to generate electricity. Same with steel production, you don't need to cool hydrogen before using it, on the contrary, high temperatures are useful in such cases. Using "hot" hydroge…
This is very interesting from an agricultural perspective. According to the Wikipedia article for ammonia, “In the US as of 2019, approximately 88% of ammonia was used as fertilizers”. To me this is a very interesting and damning fact with regards to current dominant agricultural practices. Yet another reason that it would be beneficial to further redevelop closed loop nutrient systems. For instance, sewage solids fr…
Why is depopulation not even a consideration as a solution for climate change? Surely there are ethical ways to implement it. Or do the world's largest and wealthiest nations only care for their hold on economic power?
The article points out that ammonia generates far more emissions than any other single chemical compound [1] but it is still a fraction of cement [2]. [1]: https://cen.acs.org/content/dam/cen/97/24/WEB/09724-industri... [2]: https://www.nature.com/articles/d41586-021-02612-5
https://www.wri.org/data/world-greenhouse-gas-emissions-2018
Yes, this is the case due to the enormous scale of production. Replacing the hydrogen source at similar scales with electrolysis is plausible with base load power generation. The cost increase is a small integer factor, and in the bigger scheme of things is likely something we can adapt to at least for agriculture. An obvious challenge is that we don't have available green base load power -- nuclear, hydro, or geothe…