Well, I believe Muller is half right. The world is becoming warmer. If you go back 70,000 years, where I sit right now was under a mile-thick sheet of ice. So was much of the northern hemisphere. The world has clearly been on a warming trend since then, as it gets back to it’s “normal” temperature. You see, we are still in an “ice age” as there is permanent ice on significant parts of the earth. Paleogeologists believe that has been the case only for about 5% of earth’s history.
The half Muller got wrong was the “mankind is causing this” part. There has been a lot more CO2 in the atomosphere in the past, the world has been a warmer place, and man had nothing to do with it. Nothing at all; we had an alibi. We weren’t here.
A a feature of the modern age is that some men have convinced themselves that mankind is in control of our destiny. Whether one believes in a divine providence or not, the power of nature is so overwhelming greater than the powers of mankind that this is nothing more than pure hubris. Pascal once commented to it took but a grain of sand in his bladder to reduce Cromwell, the greatest man in Europe at that time, to nothing.