They switched from "global cooling", to "global warming", to "climate change", as the data used to support either cooling or warming fell apart. More than thirty years ago, they were trying to use sea level rise as the most significant threat from "global warming" (they meant "man-made global warming", of course). Well, we have had more than 100 years of global sea level rise data to analyze, and it DESTROYS the "global warming" theory (again, too avoid any confusion, "man-made global warming" theory), thus, the reason they switched to "climate change" (and, again, insinuating "man made climate change"), is because there are ALWAYS extremes in weather, which they falsely claim is evidence of "climate change". As a scientist, it enrages me so much to see how science has been corrupted by political ideology.