That should read “The Global Warming HOAX”
First there is Historical Global Warming. We can see that from temperatures. It is pretty factual, though small. The major uncertainty is from the fact that a lot of official weather stations were located at airports for convenience, and cities have grown up around them, so the weather stations are now located in a more severe heat island than they were in the 1900s. Heat islands cool the surrounding area, so measuring only the hot part is biased, but we can censor out the corrupted sensor locations.
Then there is Anthropogenic Global Warming.
That is a guess at what causes HGW. The fact is some may be caused by us, some by volcanos, some by CO2 from the water escaping. The fraction is unknown. People that pretend to know are frauds.
Then there is Future Global Warming. We don’t know how to quantify that, can’t because of the nonlinearities inherent in the system. People who pretend to know are frauds.
Then there is Anthropogenic Future Global Warming. We don’t know how various causes of AFGW will interact, because of nonlinearities we are uncertain of the future quantities, and the degree of interaction depends non-linearly on the quantity. People sho pretend to know are frauds.