Two points:

First: According to Pew Research (no matter what the name says, it's not affiliated with any church)

For instance, the recent Pew Research survey finds that U.S. Catholics are divided on homosexual behavior, with 44% saying it is sinful and 39% saying it is not – a figure that rises to 51% among Catholic adults under age 30. And majorities of Catholics say that living with a romantic partner outside marriage (54%) and getting a divorce (61%) are not sinful. About half (49%) say remarrying after a divorce without first obtaining an annulment is not a sin.

In addition, fully two-thirds of U.S. Catholics (66%) say using artificial birth control is not a sin. Even 57% of the most devout Catholics – those who report attending Mass at least weekly – say using contraceptives is not wrong.

Those who attend Mass weekly or more are divided over the sinfulness of cohabitation (46% say it is sinful, 45% say it is not). But these Catholics also are more likely to agree with church teachings when it comes to abortion and engaging in homosexual behavior: 73% and 59%, respectively, say these are sins. Indeed, a majority of all Catholics, regardless of whether they attend Mass regularly, say abortion is sinful (57%).

Second: Burke said that the Pope isn't all-powerful. Burke should know better. Francis can speak ex cathedra and then:

Ex cathedra is the theological term for a teaching that has been declared infallibly by the Roman Pontiff. In short, ex cathedra means that the pope can explicate an article of divine revelation under the guidance of the Holy Spirit and in full possession of his role as Peter's successor. When he does so he is protected from error. This ex cathedra possibility was supported by the Second Vatican Council. However, this does not mean that every time the pope speaks he is speaking infallibly.

Even though only two doctrines have been declared ex cathedra, there are many others that the church professes must be believed. Some of these are laid out in the 1998 "Commentary on the Concluding Formula of the Professio fidei" issued by then-Cardinal Joseph Ratzinger of the Congregation for the Doctrine of the Faith.

According to this document, many teachings are "irreformable" and "definitive" and as such can be seen as possessing the binding quality of an infallible doctrine, although not necessarily proclaimed ex cathedra. That is, they aren't promulgated by the pope himself but by the larger magisterium of the church. The lineup of "irreformable" teachings—ones divinely revealed—include those regarding Jesus, Mary, sin and grace, the sacraments, the primacy of the pope, and the doctrinal formulations of the ancient creeds.

The lineup of "definitive" teachings on faith and morals—ones the church holds to be logically derived from divine revelation—include teachings such as the doctrine of papal infallibility, the immorality of abortion and euthanasia, the communion of saints, and others. Assent of "intellect and will" to both categories of teachings are required for full communion with the Catholic Church.

If Big Frankie ever came out and say, ex cathedra, that the thoughts contained in "Laudato si" were what Catholics must believe, that would be that. No further argument possible. And as it is, he chose an encyclical, and the next step up is ex cathedra.