Just about to delete the first post in embarrassment, having not searched whether electromagnetic waves can physically contribute to global warming. But ... : AI says: Yes, electromagnetic waves, or radiation, are involved in global warming through the greenhouse effect:

The full colon, according to the top rank on the internet (University of Sussex, of all places), is used to: indicate that what follows it is an explanation or elaboration of what precedes it.

But no explanation follows (for what seemed an alarming admission). It jumps straight to AI's version of Greenhouse Effect

AI hasn't got there yet with the colon, or charitably, it might indicate it's a work in progress. Which AI is.

Anyway, according to AI, electromagnetic radiation is a thing, global-warmingly speaking. I bet you could make a good circumstantial-case with graphs showing the rise of temps & the rise of electromagnetic waves. As you can with smoke pollution. Big changes are always perfect storms. An alignment of factors.

But philosophically, how would the world deal with the knowledge that the internet was plunging earth into a global-warming death spiral?

You'd have to think we're well beyond the point of no-return. Hard to see The Internet (which appeared in our lifetimes as a new God, like The Sun), suddenly fizzling out (in our lifetimes). Nothing short of a total reset is gonna do that. Maybe that's our destiny. It's how the game works.