Global warming is still a very controversial subject, calling for caution in asking the faithful to act a certain way, as this article from Catholic Culture shows.

An excerpt.

In Pope Francis’ message on climate change, made public today, he implicitly taught and explicitly applied a moral principle. “The time to find global solutions [to global warming] is running out,” Francis wrote. “There is therefore a clear, definite and urgent ethical imperative to act.” This is a particular application of the moral principle that every human person is obliged to exercise good stewardship over creation.

As a particular application, this moral counsel depends not only on the veracity of the principle but also on a proper recognition of the situation in question. In other words, if the globe is not warming, and/or human power can not do anything about it, and/or time is not running out, then the principle of good stewardship (which the Church understands infallibly) does not demand moral action in this particular case (which Church leaders must assess prudentially, like everyone else).

In contrast, yesterday’s letter by Pope Francis on the upcoming World Meeting of Families in Philadelphia stated a moral principle and emphasized the need to apply it properly, but did not specify the particular application. Here is the passage:

The mission of the Christian family is, today as it was yesterday, to announce to the world the love of God through the strength of the Sacrament of Marriage…. We are called to look again at our lifestyle, which is always exposed to the risk of being ‘contaminated’ by a worldly mentality—individualist, consumerist, hedonist—and to rediscover the high road to live and propose the grandeur and beauty of matrimony and the joy of being and making a family.

In this form of teaching, a Churchman will always be completely correct as long as he teaches according to the Magisterium. Thus, in this case, errors can creep in only when the moral principle—which is certain—is denied, ignored, or applied incorrectly by married couples in real life.

Now, to gain the same level of clarity in the first example we must recast the teaching like this: “If global warming is a serious threat, and if we can do something about it, then we have a moral obligation as the stewards of creation to reduce global warming and/or mitigate its effects.”

Retrieved December 12, 2014 from http://www.catholicculture.org/commentary/the-city-gates.cfm?id=940