The human race may (or may not) be responsible for the rise in global temperature over the past several decades. We may be in the hottest years since records were kept, or the observed “pause” in the rise in global temperatures since 1998 may give us pause as to what, precisely, is going on.

But one thing is certain: A number of people, of quite different views, have been busily heating up the debate in anticipation of the June release of Pope Francis’ encyclical on the environment.

Cardinal Oscar Rodriguez Maradiaga, who heads the Pope’s specially selected advisory committee of nine cardinals, responded to questions last month in an appearance at Georgetown University and made a point of emphasizing that the encyclical would focus more on the moral issues than on the science. The Holy See, he said, recognizes that others are in a better position to address the latter. Yet it seems that even this prudential distinction will not suffice to cool down controversy.

Indeed, it has become a kind of “meta” analysis to notice that those of a more conservative bent are pre-emptively drawing that distinction to blunt papal judgments, while those of more liberal inclinations have called the conservative move a species of “cafeteria Catholicism.” In other words, an old and valuable distinction in Catholic social thought has itself now become just one more bone of contention when it comes to the environment.

And then there’s the secular context.

A recent experience that may be illuminating: I was on National Public Radio last week, with three other commentators, discussing what the encyclical might say and the reactions to it. The first was a staffer of the Earth Institute at Columbia University, whose director — Jeffrey Sachs — is a longtime promoter of environmental measures, especially contraception and abortion, for purposes of population control.

Both were invited to Rome to participate in the Holy See’s climate-change summit in late April, and the staffer asserted that there was absolutely no dispute over the science among scientists — though for some reason he felt it necessary to rant for 10 minutes about the absolute lack of controversy.

Next up: A well-meaning Filipino Catholic, justly delighted over the Pope’s visit to his country, innocently argued that the bad storms that accompanied the papal visit were consequences of climate change — an appealing but wrongheaded claim, since scientists themselves warn about connecting warming to specific weather events.

Finally, a young Jewish woman who covers religion for The New York Times was asked to put the controversies into perspective, which she did in an informed and able way — but with an understandable tone deafness about the particular Catholic resonances of a pope talking about our responsibilities as stewards of that creation.

NPR is a kind of secular bellwether in such matters, and it was no surprise when the “moderator” laughed and wondered aloud whether, after all, any of this was very important. Does anyone listen to the Pope anymore, despite his personal charm, even on issues like the environment?

Oh, and I almost forgot: In the midst of all this, NPR wheeled out yours truly, crazy old Uncle Bob — I think just to be able to say that they had. On these occasions, you let him talk enough so as not to insult him while keeping him on a tight leash, but then move along quickly to what everyone who’s anyone knows are the right approaches to these questions.

That’s the general, secular fog that the encyclical will have to cut through in a few weeks.   

Just to lay out where I stand personally: It seems to me, as a one-time student of science, that putting fair-sized amounts of carbon dioxide into the atmosphere must have some effect. It’s simple chemistry and physics.

How large and dangerous an effect is difficult to say, because the Earth doesn’t allow us to conduct controlled scientific experiments, whatever the scientists and politicians may have told you. In a real experiment, you have a control system and an experimental one. You change one variable in the latter and observe the results. Done right, you can then say that change X produces result Y.

Climate cannot be subject to such an experiment because there are too many variables, and they’re varying all on their own, even as you’re trying to look at what may be the man-made effects. In the extreme case, you might very well observe all sorts of signs of warming and be fundamentally wrong on the cause because there’s no way to demonstrate cause and effect conclusively.

Further, the computer modeling has not been particularly accurate. Projections have been much higher than the observed reality. Indeed, that “pause” since 1998 has scientists wondering whether oceans are absorbing the extra heat — which may bring yet further problems — or it just may be that the climate is not as sensitive to carbon-dioxide changes as was previously thought. So you want to be constantly checking and rechecking your data and recalibrating assumptions — if you really want to do what’s good for the environment.

This, it seems to me, is what a fair-minded person would want to argue in a Catholic or a secular forum. But good luck getting a hearing in either place.

These subtleties and uncertainties about the science are likely to be overwhelmed by equally unwarranted certainties, in several quarters, about our moral responsibilities. We’re already seeing progressive Catholics gloating over a chance to use the Pope to beat up corporations, oil companies, globalization, meat eaters and other alleged malefactors. The right worries about what unnecessarily stringent environmental measures may do to economic growth, and, along the way, to the very poor Pope Francis has expressed a hope of helping via environmental concerns.

“Prudential judgments,” controversies notwithstanding, are essential here. For instance, there are actually two kinds of “poor.” Each side emphasizes its favorites: Progressives only think of the poor as living in low-lying coastal or tropical areas, who will have their already-precarious lives disrupted if sea levels rise or temperatures spike. Of course, this warrants moral consideration.

But there are also billions of people who desperately need good, old-fashioned economic development — clean water and electricity, for starters — along with responsible government to make sure they can enjoy development peacefully. They, too, should be on our moral radarscopes. In fact, the other group of poor desperately needs development, as well.

It’s likely most of these concerns will be mentioned in the encyclical, but just to notice them is to see — even on the “moral” questions that the Vatican intends primarily to highlight — that there are not only complexities, but conflicting goods, in play. We no longer live in the Garden of Eden and can’t return there until the day when God returns and gives us a New Heaven and a New Earth.

You won’t hear this on NPR after the encyclical is published. And it may be difficult even for Catholic outlets to hold the balance steady. But we need a careful prudence and appreciation of unknowns in dealing with these matters. Resources are always limited and present us, usually, at least in these sorts of matters, with choices about better and worse, not outright good and evil.

The humble but useful term “trade-off” isn’t a battle flag for either camp. But for those of us who care both about the physical environment and what several popes now have called the “human environment,” it may be a notion that we will all want to become much more familiar with in coming months.

Robert Royal, Ph.D., is the founder and president

of the Faith & Reason Institute in Washington

and editor in chief of The Catholic Thing website.