The data isn't being "shifted", and it's not arbitrary. Again, the graphs are being used to illustrate changes in temperature, not actual temperatures. And, aga

The data isn't being "shifted", and it's not arbitrary. Again, the graphs are being used to illustrate changes in temperature, not actual temperatures. And, again, this is a very simple analytical tactic. This is not unlike a non-programmer being skeptical of Quicksort because it's "arbitrarily dividing data".