Do you have some kind of pointer to a summary of what concrete impacts it actually has? Like, the article here doesn't list any concrete material. I see some phrases like "20% of land and sea". Given that Hungary and Austria were apparently both reluctant and both are land-locked, I am wondering if it was "20% of land and sea", where sea can substitute for land.

Does it basically ask EU members to designate at least 20% of their territory as a sort of national park?

The EC has a section on their website on the thing, but it's...really fluffy and full of marketing material. Their factsheet on the law is...very sparse on actual facts about the law.

EDIT: This Wikipedia page seems to reference what is a superset of it:

https://en.wikipedia.org/wiki/European_Green_Deal

But the targets there don't seem to match up with what is going through, like:

The EU Biodiversity Strategy for 2030 includes the following targets:

• Protect 30% of the sea territory and 30% of land territory especially primary forests and old-growth forests.

...whereas the law that went through uses "20%".

EDIT: Okay, that's definitely a superset of what was planned for the law, because the page does reference the targets that were actually taken being 20%.