One common trope among climate change deniers is to point out that, in the 1970s, everyone was a panic about global cooling, even to the point of predicting an imminent ice age. If they were so spectacularly wrong back then, the argument goes, why should we be listening to them today?
The argument rests on an equivocation. In the 1970s, "they" refers to a handful of scientists making tentative predictions, and a handful of journalists who repeated those predictions. Today, "they" refers to every single major scientific body in the world. There's just no valid comparison.
In fact, back in the 1970s, more scientists were worried about global warming than its opposite. As USA Today reported last year, Thomas Peterson of the National Climatic Data Center surveyed 71 peer-reviewed articles from 1965 to 1979 and found that only seven predicted falling temperatures. Some 44 predicted warming, and another 20 were neutral.
William Connolley, a climate modeler with the British Antarctic Survey, has attempted to collect everything that was written in the scientific and popular press about global cooling in the 1970s and compile it on a single Web page. That page is about as long as the one you are viewing right now.
Try doing the same with everything written about global warming. How long would that page be?