On May 16, 2013, President Obama tweeted that “Ninety-seven percent of scientists agree: #climate change is real, man-made and dangerous.” The President is one of countless people who have come to believe that there is a “97% consensus” on anthropogenic global warming (AGW).
Since it is inconceivable that any climate scientist today could have no opinion on the subject, if 97 percent accept AGW it follows that 3 percent reject it. To those outside of science, 3 percent may seem an insignificant percentage. However, we scientists know that a small minority has often turned out to be right, otherwise there would have been no scientific revolutions. In the 1950s, for example, the percentage of American geologists who accepted continental drift was likely less than 3 percent. Yet they were right.