Deflecting a bit from legislators claiming that it was oil companies "blocking legislation". Sure, they lobbied but who are the ones with the pen in hand?
Did you forget that "Big Oil" knew about global warming all the way back to the 70s; Then spent decades lying to the public and legislators both about it?
So who is more culpable? The legislators who didn't know better, or the executives who did, and lied to them?
The corrupted, or the corruptors?
Climate change has been in the public discourse since at least the 80's, so legislators did know. It just hasn't been in their interests to acknowledge it.
The Venn diagram of public discourse and legislator knowledge isn't a circle.
And the public discourse was filled with FUD from Big Oil, no place more so than the halls of congress.
I understand your point but let's not ignore that fossil fuel corporations have made campaign donations and contributions to legislators for as long as those corporations existed. Whether or not legislators totally bought into the FUD (and I'm not sure all did, the same way not everyone in the wider public discourse bought into it) it was literally not in their interests to legislate against fossil fuel.