When an elderly Pope Leo XIII released a document in 1891 on the rights of workers to unionize and of owners to hold private property, European capitalists and socialists alike cried foul. Why should we listen, they fumed, to a pope’s pronouncements on economics and politics?

Now, 124 years later, Pope Francis has set off an uproar over his document on the environment and the threat of climate change, an encyclical released Thursday called "Praise Be to You: On Care for Our Common Home."

Once again industrialists, politicians and critics are fuming, contending that the pope should stick to religion and stop meddling in matters in which he has no competence.

"Pope Francis’ message on global warming was a confusing distraction that dilutes his great moral authority and leadership at a time when it is desperately needed to combat real — and present — crises in the church and in Western culture," said Richard Viguerie, who pioneered the use of direct-mail fundraising to help build the political and religious right.

But Francis is following in the footsteps of popes and bishops who, for generations, have written documents on pressing social problems by applying religious teaching to events so contemporary that they seem ripped from their eras’ headlines.

Pope Leo’s encyclical "On the Condition of Labor" — or "Rerum Novarum" in Latin — became the seminal document in what is now recognized as modern Catholic social teaching.

Yet there have been many since then. Pope John XXIII warned of nuclear annihilation in "Pacem in Terris" in 1963. Paul VI challenged wealthy nations to help develop poor nations in "Populorum Progressio" in 1967. Benedict XVI noted economic inequality from globalization in "Caritas in Veritate" in 2009.

Still, Francis’ encyclical, contends Austen Ivereigh, a papal biographer in England, "is the most significant Catholic social encyclical since the first, Rerum Novarum in 1891, and it is very much within that tradition."

What distinguishes "Laudato Si’" from previous church documents on the environmental crisis, Ivereigh added, is that it is intended to provoke action — to cause an enormous "conversion" in how human beings understand their place and responsibility to a planet that is in peril.

"We all know this is happening; the church has been talking about it for a long time," Ivereigh said, paraphrasing Francis on environmental destruction. "Yet we do nothing."

In "Praise Be to You" Francis puts forward a profoundly theological document, grounded in Catholic teaching but one in which spiritual and secular matters are knit so closely together that the table of contents promising to segregate them into sections is a bit deceptive.

Like a recurring chant, Francis intones throughout the document that everyone and everything is interconnected — to God, to creation, to fellow human beings.

The encyclical repeatedly invokes phrases like "brother sun, sister moon, brother river and mother earth." Praise for "our Sister, Mother Earth" comes from the canticle "Laudato Si’" by St. Francis of Assisi, for which the encyclical is named.

"As believers, we do not look at the world from without but from within, conscious of the bonds with which the Father has linked us to all beings."

But just when he begins to sound spiritually cosmic, he adds a pinch of science: "A good part of our genetic code is shared by many living beings."

Francis seems intent on showing that the concern about the environment is not his alone.

For at least three decades, bishops’ conferences and popes have spoken out on environmental problems. Francis’ encyclical is studded with quotations and footnotes from the statements of bishops in countries like Australia, Brazil, Canada, the Dominican Republic, Japan, the Philippines and the United States on the impact of climate change or environmental crises.

For some of Francis’ most contentious arguments — about an economic system that exacerbates inequality and causes environmental degradation — he cites the words of his predecessors, especially St. John Paul II and Benedict XVI.

He attributes the environmental crisis to wealthier, industrialized countries that extract resources to feed an insatiable desire for consumer goods. Christians also, he said, have been seduced by this consumerism, despite the tradition of monasticism and teachings on simplicity by St. Francis and others.

"Christian spirituality proposes an alternative understanding of the quality of life, and encourages a prophetic and contemplative lifestyle, one capable of deep enjoyment free of the obsession with consumption," Francis writes. "We need to take up an ancient lesson, found in different religious traditions and also in the Bible. It is the conviction that ‘less is more.’"

Early in the encyclical, the pope spells out his intent for all humanity to undergo a spiritual transformation: "Our goal is not to amass information or to satisfy curiosity, but rather to become painfully aware, to dare to turn what is happening to the world into our own personal suffering and thus to discover what each of us can do about it."

He says that the Bible’s reference to human beings having "dominion" over the earth has been misread by some Christians as giving license to humans to plunder its resources without respect for other living organisms.

Francis notes that in the Book of Deuteronomy, it says that if you come upon a bird’s nest in a tree with a mother sitting upon the eggs, "You shall not take the mother with the young."

And in Exodus, it says that the Sabbath day of rest is not just for humans but also so that your ox and the donkey can rest.

"Clearly, the Bible has no place for a tyrannical anthropocentrism unconcerned for other creatures," Francis writes.

These ideas are at the core of Franciscan spirituality, inspired by the life and teachings of St. Francis of Assisi, the 13th-century friar and Pope Francis’ namesake, said Patrick Carolan, executive director of the Franciscan Action Network, a coalition of Franciscan orders that works on social justice issues.

"You hear the stories of Francis going out and preaching to the birds and the trees," Carolan said. "We tend to regard this now as some hokey Dr. Doolittle story. But St. Francis was asked why he did this, and he said God had asked him to preach the gospel to his brothers and sisters, and he considered those his brothers and sisters."

"We Franciscans, we’ve been at this for 800 years," Carolan added. "So welcome to our party."

Francis seems determined to remind Catholics, at least those in the Americas, that to see nature as a living sibling is not a foreign concept found only in Native American spirituality but part of their own Catholic tradition.

Francis praises non-Catholic leaders who have put care for creation at the center of their teaching, like Patriarch Bartholomew I of Constantinople, who leads the world’s Eastern Orthodox Christians.

Among those presenting the encyclical at a Vatican news conference Thursday was an Eastern Orthodox theologian, Metropolitan John Zizioulas, who said, "The ecological crisis is essentially a spiritual problem."

"The proper relationship between humanity and earth has been broken by the fall, both outwardly and within us. This rupture constitutes what we call sin.

He said, "The church must introduce in its teaching the sin against the environment. The ecological sin."

© 2015 The New York Times Company