When would skepticism NOT be reasonable?

When would skepticism NOT be reasonable?   “Well, when would skepticism NOT be reasonable is when you have a confirmed fact.” I am a rationalist atheist and am only skeptic if it is warranted and reasonable to do so and it is not always reasonable. So I don’t put the same believed value in skepticism that skeptic atheists insist it has. However, I don’t at all see where there would be that much different between Skepticism and atheism to have many issues unless the atheism is religious leaning or fully religious atheism or the skepticism is religious pseudo-skepticism (denialism) or solipsism skepticism.   “Denialism is the refusal to accept well-established theory, law, fact or evidence. In scientific contexts, the denialist can deny a cause (carbon dioxide does not cause global warming), an effect (the Earth is not warming), the association between the two (CO2 levels are rising and the Earth is warming, but not because of the carbon dioxide), the direction of the cause-and-effect relationship (carbon dioxide concentrations are increasing because the earth is warming) or the identification of the cause-and-effect relationship (other factors than greenhouse gases are causing the Earth to warm). Often denialists practice minimization (the Earth is warming, but it’s not harmful) and use misplaced skepticism to give an unwarranted veneer of scientific thinking. Major scientific targets of denialism include evolution, global warming, the link between HIV and AIDS, the link between smoking and lung cancer, and evidence that there is no correlation between vaccination and autism. Often self-interest is the motivation behind denialism, hence arguments are often politicised or financially motivated. For example, tobacco companies...