To say that this letter is "factually wrong" is a polite understatement. Moreover, the letter is internally inconsistent, a sure sign of major fallacy. There is "no global warming" the writer claims, even while he admits that "the melting continues to this day". The writer is someone who has not given serious thought to the matter, as evidenced by the opening sentence: "The believers in global warning are carefully to avoid history, geological history."
I think he MEANT to write "global warming", but didn't bother to take care to write what he actually meant. And I believe that the substitution of the adverb "carefully" for the adjective "careful" is a "careless" mistake. 
Global warming is REAL; it is caused by massive combustion of fossil fuels; and it is dangerous because it is happening so rapidly that it is ecologically disruptive.