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Comment by cpursley | Hacker News Reader

It’s not just about energy, but also industrial (think neon, helium) and agricultural inputs (nitrogen, urea). Even if energy was solved, there’s not really replacements for these. Well, regenerative agriculture but not sure that will feed as many people.

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The nitrogen comes from the air - we're perfectly capable of capturing it using renewables.

It's probably one of the last things to be created that way because it's one of the places where methane is used more efficiently than burning it... But fundamentally there's no issue here except energy availability and a short term supply shock.

The nitrogen in generated fertiliser comes from the air, it’s the hydrogen in the process that comes from natural gas.

You can theoretically get it from water instead, but the energy cost is something like 3-4 times as high. It may be feasible at some point.

Also, you can't make plastics out of wind power or out of solar, you still need the "petro-" that's part of the petrochemical industry.

You can use solar to convert CO2 into syngas and do a Fischer-Tropsch synthesis followed by polymerization to get plastics.

You can make plastics out of cellulose, which is available from plant sources or organic (algae) bioreactors.

It would take a while to retool the plastics industry to use organic sources, but it's not at all impossible.

Is there enough cellulose available to keep Temu fully stocked? Now and in the near future. And aren’t you going to get agricultural land out of the equation in order to have space for that cellulose-planting industry? And in so doing increasing the price of basic food.

This is false, you can make many plastics without fossil sources (pla, bio-pet, bio-abs, etc). The only challenge is cost and scale - it's cheaper and easier to use existing processes.

> challenge is cos

So you can’t.

And how exactly do you think all of those agricultural products are produced? They require an insane amount of diesel fuel and nitrogen fertilizers…

Plastic packaging can be substituted. Engineered plastics are a tiny fraction of petroleum.

It’s not about packaging, Temu/Shein are not selling packaging.

But making plastics using renewable energy and fossil hydrocarbons for feedstock does not exacerbate the greenhouse effect, unless you burn them when you've finished with them.

Arguably plastics are a stable, cheap and useful carbon sink and if climate is the overriding ecological priority we should be making as many as we can and recycling as few as possible.

Using renewables means you're burning up less of your plastic feedstocks.

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