Can someone answer a dumb question for me: plastics are made from petroleum, a class of molecules that has been in the ground for hundreds of millions of years, but are bad because plastics take a long time to degrade?
I don't understand. The thing they are made from apparently takes hundreds of millions of years to degrade!
Sure, the thing that you're missing is that there's extremely strong evidence that these plastics:
1. Don't degrade quickly (per your point)
2. Are difficult to mitigate/filter (per article's point)
3. Are appearing everywhere, including in our water supply, food supply, adult human tissue, and within fetuses still in their mothers' wombs
4. Critically, and probably the point you're missing, they are disruptive to endocrine systems (hormones) which are extremely important to all sorts of developmental, behavioral, and psychological systems, including negative effects on fertility, e.g. a child born to a microplastic-poisoned mother will have reduced sperm count in adulthood. This is a bad thing, and in combination with points 1-3 is potentially catastrophic for human civilization.
I'm not an expert, but oil wreaks havoc to nature and life, if it spills. So there is problem nr 1. I don't know how much time nature needs to rebound from such spills, but I know, that (crude) oil on beaches makes them unhabitable for years.
Problem Nr. 2: plastics made from oil are different from, well oil. They're a product, that doesn't occur in nature, as far as I know.
Plastics are hormonally active in the body. There might be thousands of different plastics and nobody really knows how they're reacting with animals, nature and so on.
But the short answer is: petroleum kills, that stuff is dangerous as hell.
I guess if you are on team carbon sequestration, plastics are better than burn and release into atmosphere. If you are on team plant life, more carbon = more vegetation.
I don't understand. The thing they are made from apparently takes hundreds of millions of years to degrade!
I must be missing something important.