"But, he explains, it’s just a trick created by pretending that all the scientists who agree that humans make a contribution to global warming (ie almost everyone) also agree with the alarmist theory that global warming is catastrophic, unprecedented and within man’s control. Which simply isn’t the case."
That sums it up pretty well.
I've encountered few actual humans in reality who "deny" climate change is occurring or that humans affect the environment. That strawman is pumped up to keep it hot in the political venue. Anyone who scoffs at the most extreme interpretations is accused of "denying" the phenomenon in its entirety, especially on social media.
However I've met innumerable soccer moms and liberal coeds who think climate change refers to catastrophic events within the next 10 years that we can avoid via hemp clothing. "Science" to them is a small church where all of the "official Scientists" meet once a week to issue a decree, and if Teenchick Magazine alluded to the atmosphere raining fire by 2020 then that's what Science (capitalized) has decreed.
Don't argue with them. They are conditioned to think that anyone correcting them is a "climate change denier".
Smoothly AGREE with them and link them to mainstream, non-controversial, EU/UN-backed studies on climate change -- casually point out to them how interesting it is that many of these events are projected to take place 1,000 years from now, that we merely hold the power to accelerate or decelerate the inevitable process, and that the outcomes will be a mixture of beneficial and detrimental depending on region.