I think it'd be better for science and the world in general if people would use the word skeptic instead of denier. With all this current discussion of tribalism in American politics, perhaps the lens could be turned on the language we use to describe scientific communities.
I could also point out that proponents of the anthropogenic climate change doomsday scenarios remind me quite a lot of Camping's May 21st Rapture crew. The truth is, "the end is near" has been an odd human fixation for just about as long as anybody can tell. This merits skepticism.
Regarding the conclusions of the so-called "Supreme Court of Science," as at least one person has described the National Academy---or the IPCC and other organizations---I think it's important to remember that these too are groups of people with enormous stakes in pushing the consensus toward an anthropogenic global warming dialog. However, this is not necessarily for the sake of the world; I don't think anybody actually believes any of their worst-case scenarios will actually come to pass. Rather, they have invested their entire careers and livelihoods on these claims. If they turn out to be false, then these particular scientists and politicians would be disgraced. While politicians are apt to pivot gracefully out and shift the dialog to their benefit, scientists tend not to take so well if their ideas are discredited.
It seems that climate science---as distinct from meteorology---had never been a particularly interesting field until these sorts of worldwide catastrophe scenarios began to gain traction (correct me if I'm wrong here). Our tools to observe these large-scale changes are relatively new, of course; the problem is, since we've only had the ability to peek into the atmosphere or the ozone for a few decades, the discipline doesn't have centuries of quack claims or false alarms at hand to give the field an even temperament.
Finally, "science" is not at all monolithic---and I don't mean simply that there continue to be folks of different opinions. There are many different ways to gain so-called "scientific" knowledge, and they all generally fall under the umbrella term of empirical methodologies. There are hypothesis-driven studies which are able to directly manipulate experimental conditions, correlative studies which take advantage of previously existing variations, exploratory studies which just start measuring and hypothesizing, and there are modeling studies such as those used in climate science.
Modeling studies by far are the least intrinsically reliable of these, since they excel at showing potentially plausible explanations but operate based on many assumptions and proceed in microchips instead of on a lab bench. There have been innumerable takes on scientific philosophy as well. Perhaps you're familiar with Popper's case for the necessity of falsifiability in a scientific claim. Although this is only one approach to scientific reasoning, it has certainly been particularly fruitful for modern-day consensus building. One major problem of these climate models is that they get revised again and again and again based on new incoming information---parameters are revised, but the models as a whole are never thrown out.
It's an interesting question, and I think that good healthy skepticism is exactly what people need in order to truly advance scientific knowledge. Not name-calling.