That's neither here nor there. He hasn't cast any doubt, he's simply said things that are contrary to reality. Much as he has done in the past and continues to do.

There's two schools of reality...

1. Reality is what we observe and have empirical evidence of.

2. Reality is what what the most vocal group says it is.

Anti-intellectualism has given us #2 and now it's in control and probably cannot be stopped for a long time.

Welcome... to the future.

I disagree. It's pretty clear Trump was very effective in framing the entire narrative in a way that helped people doubt. Trump was very effective at this- he's almost an idiot savant at twitter.

Yes, contrary to reality, his 'alternative facts'. Which are unfortunately the speak of the administration.

Doupleplus good! /s

the phrase 'cast doubt upon' doesn't necessarily imply that anyone was persuaded, although it would be remiss of me not to observe that there is a willing audience for such specious claims. OK, this is about as productive as trying to have a debate about the existence of ghosts* with someone who isn't even interested in designing experiments, but that's the world we live in right now.

It does infer that it brought something into question.

Which is not what Trump did here. Climate change is still about as unquestionable as it has ever been.

Denying it is on the same level as denying the holocaust happened. IMO we should treat climate change deniers exactly the same way.

I agree with you 100% about climate change but disagree about the implications of the phrase. I'll spare you a long etymological argument as to why, suffice it to say that I read the phrase as descriptive only of Trump's intention rather than whether anyone else found it persuasive.