Humans have always used denial. When we are afraid, guilty, confused, or when something interferes with our self-image, we tend to deny it. Yet denial is a delusion. When it impacts on the health of oneself, or society, or the world it becomes a pathology. Climate change denial is such a case. Paradoxically, as the climate science has become more certain, denial about the issue has increased. The paradox lies in the denial. There is a denial industry funded by the fossil fuel companies that literally denies the science, and seeks to confuse the public. There is denial within governments,...