Think about it.
Pope Francis may be teaching as supreme pastor, but he is not teaching on a subject which is a matter of faith or morals, ad he has certainly not indicated that the teaching is infallible.
In fact, when we have time to examine the encyclical more closely I think we’ll find that there is a good bit of opinion, conjecture and theoretical language in the document. Francis is not much of a dogmatic teacher, but more intuitive, tentative and suggestive.
So the simple answer is, “You can disagree with the pope about global warming and still be a good Catholic.”
Furthermore, encyclicals are sometimes addressed only to the Catholic faithful. Their teaching would be assumed to be more authoritative and binding. Pope Francis has addressed Laudato Si to all people. He is therefore not delivering teaching which is binding, and within the encyclical he speaks of the need for dialogue, discussion and growth in learning on these matters.
However, you’re not supposed to just ignore papal teaching. It is true that the faithful must listen carefully, respond with an inner disposition of obedience and submission to papal teaching and seek to conform one’s life to the teaching.
Therefore I’d conclude that you can disagree with the pope about the reality of global warming and it’s causes, but you should listen carefully to the whole of his teaching and take on what he says about the ecological crisis the world is facing. We should listen carefully to his teaching about pollution, the destruction of habitats and natural ecosystems. We should heed his warnings about the destructiveness of unlimited consumerism, the “grab and throwaway culture and the abuse of the vulnerable, poor, immigrants and disabled.
In other words, embrace the whole thing with love and a desire to learn. Pay attention to the real crisis we’re all facing and alter your lifestyle. however, if you can’t swallow the global warming caused by humans you’re allowed to still be skeptical.