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Comment by ksdale | Hacker News Reader

Are bio-plastics really a big improvement though? Growing corn burns a lot of fossil fuels. I think there's a case to be made that plastic that ends up in a landfill after few carbon emissions is better for the environment than plastic that degrades after lots of carbon emissions. Not saying that's definitely the case, just that I'm not sure it's so clear.

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> Growing corn burns fossil fuels

Head-scratching a bit there. Corn absorbs CO2 while growing right ?

From https://www.agweb.com/article/corns-carbon-cowboy-busts-outs... ...At 200 bu. per acre, every acre of corn absorbs 8 tons of carbon dioxide. In 2012, U.S. farmers grew almost 100 million acres of corn and absorbed 800 million tons of carbon dioxide...

Tractors, combines, trucks - there's a lot of heavy equipment that gets used to grow corn, and then there's emissions related to both producing and applying fertilizers.

There's the old quip that corn is just one small step in the chain of converting oil into something people can eat.

The assumption there is that plastic emits less carbon when it's being created than corn. Is that accurate?

There is also a land cost. I'd be surprised if we determined that plastic is better than bio-plastic, but until we are making bio-plastic with a low land footprint land will continue to be a factor here.

This might be a really stupid question, but how does land factor into carbon emission?

I think the issue isn't emissions in that case but a "amount of land space necessary for landfills for traditional plastic" vs. "amount of land space necessary for plant growth for bioplastic."

If the bioplastic growth land takes up more space by a certain amount than is used to dispose of regular plastic, that's presents its own set of issues.

I believe that pulling oil out of the ground is way less carbon intensive than growing the necessary amount of corn, and I believe plastic is made from some tiny fraction of the petroleum that isn't used as fuel, so the petroleum would be extracted anyway, but the corn would not be grown anyway. I'm assuming the actual production of the good itself is similar in either case.

In some ways, yes, and in others, definitely not. I think we'll get there: I also think some plastics are made using byproducts of fuel (gas/diesel) production, and as long as that's the case, we should probably use and recycle that (or find something else to do with it). Kind of like using every part of the animal, except with oil.

https://phys.org/news/2017-12-truth-bioplastics.html

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