Why is it better to use plant and animal based products in place of petroluem and plastics?

This is my midterm essay question which I have researched on my own. But I am at a loss.

Here’s one thing:

The manufacture of ammonium nitrate fertilizers (which uses natural gas as it’s hydrogen source) is very energy intensive. 1.2% of global primary energy demand goes to ammonium nitrate production. In the process, huge amounts of greenhouse gasses are created.

It would be virtually impossible to feed the world without using ammonium nitrate fertilizer, but there are ways of extracting hydrogen from biomass (e.g. straw) instead of from natural gas. That would potentially reduce greenhouse gas emissions by 22–30%.

Here’s one study, if you need a reference.

Thanks but I can’t buy the study. So I could say that they are better in reducing the emission of greenhouse gases.

You don’t have to buy it. Chances are your library can give you access to it.

You beg a question. That it is in fact better. If you can’t prove the original premise, you can’t argue the following premise without fallacy, obfuscation or lying.