OK, I saw the video.
Let’s say that preparing for the worst that can happen is a good policy. Can you imagine what would happen to our daily lives, in all its aspects, if instead of trying to be realistic about the odds of something happening, we acted as if we always feared the very worst that could happen? Perhaps we would hide under our beds all day long, if we could imagine the direst possibilities.

Also, it creates a false dichotomy. We don’t merely have the choice of going to two extremes and acting now on the most severe worst-case scenario. At this time, for the past decade, there has been no warming, and even some slight or trivial cooling, since 1998 is said to have been the warmest year.

Suppose, on the other hand, there is warming, and it may turn out to be a severe problem in the future. (Recall that in the early 1970s, there was a fear of a new ice age — Time magazine even had a cover article spreading the panic about it.) We could study the possibility of geoengineering approaches to combat the warming — such as using stratospheric aerosols. This could be done vastly more inexpensively than what has been proposed, and it would be a more robust approach that didn’t depend on the carbocentric hypothesis that all climate change is due to man-made carbon dioxide.