Ray Suarez on the Newshour did a long piece on a "new" study of global warming. A U of Maryland professor talked, and talked about dreadful consequences. In a good five minute talk he did not mention a single number. Things were going to get bad, but he did not offer any numbers to tell us how bad, how soon, or how certain.
William Thompson, Lord Kelvin once said " When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; "
Ray asked his guest how his team had come to their fairly predictable conclusions. Answer: We reviewed the published literature. That's a real confidence builder. The published literature is vast and supports every conceivable viewpoint. Most likely this team included articles that agreed with their preconceptions and ignored articles that they disagreed with.