Science is all about skepticism. We demand data, and ANY theory must be able to submit itself to an experiment that could possibly disprove it. If it cannot, then it is NOT science. If an experiment disproves it, then the theory is wrong, period. However, when you reach a mountain of well understood evidence, those who refuse to believe it are no longer skeptics. Some folks call them conspiracy theorists or crack-pots etc. The dividing line can be blurry for a time, but eventually most people are able to see where it’s located. Think about things like chem-trails, the Moon landing is a hoax, etc.

The video below from NOAA shows why denying that the planet is warming, and that warming is due to humankind, has also silently moved out of the skeptic arena. It was subtle and perhaps you did not notice it, but it has happened.
Evidence matters, and in the end it always wins.