It is a rare document that cites The Divine Comedy, the works of Thomas Aquinas and the Basel Convention on hazardous waste. There cannot be many modern communications that, in place of emojis, give us quotations from St. Basil the Great along with the phrase "synthetic agrotoxins."

Only one such document appeared this week and it was, of course, Laudato Si (Praise Be), the papal encyclical on climate change. As a former Catholic who is still angry at the church on a number of fronts, I was prepared to pick holes in Pope Francis's lengthy treatise, but instead came away quite awestruck: He has hit this one out of St. Peter's.

First, you have to consider the profound weirdness of the situation we find ourselves in. Here is an institution founded on the mystical precepts of virgin birth and transubstantiation, trying to prove to disbelievers the very science that has been staring us in the eye for decades. The Catholic Church, which still clings to miracles and exorcism and continues to turn mortals into saints, also acknowledges that climate change is man-made, empirically proven, and is devastating to the world – concepts that a wide swath of allegedly rational people refuse to believe. It's as if Pegasus said, "Look, there are these things called horses … "

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Perhaps because he is beholden to no one – being the Pope and all – there is a remarkable and quite refreshing lack of hedging or equivocation in Laudato Si. The world is imperilled. The poor, especially, are imperilled owing to the greed and obliviousness of the rest of us. All things are connected, even if we are willfully blind to the connections. "Things are now reaching a breaking point, due to the rapid pace of change and degradation; these are evident in large-scale natural disasters as well as social and even financial crises, for the world's problems cannot be analyzed or explained in isolation."

There has been a hole in the climate-change argument – a hole of grandeur, or compelling narrative, or moral authority. The densely packed reports of the Intergovernmental Panel on Climate Change are vital but they don't stir the heart. The weasel words of politicians are designed to drive us to drink. No UN report will ever say, as the papal encyclical does, that "Rather than a problem to be solved, the world is a joyful mystery to be contemplated with gladness and praise." More to the point, no official report would state quite so bluntly, "It is remarkable how weak international political responses have been."

For this, Pope Francis has been excoriated by right-wing critics as "a Marxist," "an eco-wolf in Pope's clothing" (points for bonkers metaphors), and, my favourite, "a water boy for the UN." Climate-skeptic U.S. politicians, who normally have few problems citing the Almighty as their policy adviser, cried foul when some foreigner in a white robe did the same. Said presidential hopeful Jeb Bush, "I don't get economic policy from my bishops or my cardinals or my pope," while Texas Representative Joe Barton said, "I don't consider him an expert on environmental issues."

Which is odd, since leading Republican lawmakers haven't been shy about bringing God into the climate-change debate. James Inhofe, who just happens to chair the Senate's powerful environment committee, has repeatedly cited biblical verse as proof that God, not man, controls the climate (and presumably the rising waters, having been through this once before with Noah).

What we have here, essentially, is competing belief systems. And no, I don't mean Catholic versus Southern Baptist. The climate-change debate is less about science than it is about belief – if it were about facts, there would be no debate. Instead, as George Marshall points out in his valuable book about the psychology of climate-change denial, Don't Even Think About It, people choose one camp or another based on what groups they see themselves belonging to, and which world view they want reinforced. One of the problems, as Mr. Marshall explains it, is that this issue in its complexity resists the pull of a sweeping narrative arc: "The view held by every specialist I spoke to is that we still have not found a way to effectively engage our emotional brain in climate change."

Is Pope Francis providing the grand message needed, the call to a spiritual and environmental revolution? There will be those who call into question the church's authority on any temporal matters when it still hasn't made amends for or properly acknowledged the monstrous abuse scandals of its recent past. Other people, and I'm one of them, will be put off by the encyclical's insistence on the sanctity of the human embryo and its denouncement of abortion. But perhaps we can pick and choose the wisdom that speaks to us, and discard the rest, as "cafeteria Catholics" have been doing for decades.

When it comes to belief systems, for this one time I'm with the guy who quotes Dante, and is worried about the inferno here on Earth.