Canon 752: “While the assent of faith is not required, a religious submission of intellect and will is to be given to any doctrine which either the Supreme Pontiff or the College of Bishops, exercising their authentic Magisterium, declare upon a matter of faith or morals, even though they do not intend to proclaim that doctrine by definitive act. Christ's faithful are therefore to ensure that they avoid whatever does not accord with that doctrine.”
Canon 753: “While not infallible in their teaching, [Catholic bishops] are the authentic instructors and teachers of the faith for Christ's faithful entrusted to their care. The faithful are bound to adhere, with a religious submission of mind, to this authentic Magisterium of their Bishops.”
As Protestants typically do with Scripture, you have found a PHRASE in Canon Law that you think makes your point, and ignored the SENTENCE, the CHAPTER, and the BOOK.
Catholics owe the Pope and bishops “religious submission” of intellect WHEN THE SUBJECT MATTER IS THE CATHOLIC FAITH. Re-read the two canons you cut-and-pasted, and notice that according to both of them, the Pope and bishops have the authority to teach THE FAITH.
The temperature of the Earth is NOT part of the content of the Catholic Faith. The Pope abused his authority when he asserted in an official document that the Earth is warming. He abused his authority in two ways: 1) by making ANY statement on that subject; 2) by making a FALSE statement on that subject.
Every Catholic is perfectly at liberty to declare in public that the Pope and those bishops supporting him are all abusing their office. They are exploiting the prominence that their office gives to promote their personal political notions, and those notions are false and totalitarian.