as there are so many others (approximately 95% of the world's scientists) that are far more scientifically knowledgable that have made the case for the presence of climate change caused in great part by man.
This has (I have) beaten this to death on these boards lately on how this is a vast misrepresentation of reality and of course unscientific to begin with.
If you actually dig back to the orig paper that gets cited ad nausea as making this consensus claim you will find that the wording was highly innocuous and filled with caveats to the effect "it is likely there are some anthropogenic factors". In fact several scientist that are called deniers have publicly stated they are part of that vague 98%. This is nothing close to how this quote is used, to make the claim to the nature that "the science is settled", "we know it's man", etc etc.
It is a lazy (unscientific) argument used to shutdown discussion.
This was purely a bone that Trump threw to the slim majority of his core base that ignores, or choses to disbelieve, the presence of climate change, or think their coal mining and manufacturing jobs are coming back.
That's a pretty absurd claim. As someone that didn't vote for him and isn't part of any partisan base because I like to think for myself and as a few others have already quite well pointed out there are excellent reasons for the US not to sign the accord that have zero to do with being science deniers.
But, this is a pretty common protocol today, if someone disagrees with someone else (particularly politically) there cannot be any good reason, it must be because of the most cartoonish strawman the opposition can conjure.
I also think it's worth noting that despite not signing the Kyoto protocol previously, the US actually met the emission reductions anyway via natural market/economic changes whereas many countries signing the kyoto protocol didn't meat theirs.
Signing a non-binding piece of paper means nothing.