Destroying the environment is a sin, Pope Francis said in a message from Vatican City.

"Global warming continues," the pontiff said in a message released Thursday. "2015 was the warmest year on record, and 2016 will likely be warmer still. This is leading to even more severe droughts, floods, fires, and extreme weather events."

Pope Francis has sought to highlight the importance of environmental stewardship in his speeches.© Mazur/catholicnews.org.uk

He would like "caring for the environment" to be added to the traditional Christian works of mercy, which also include visiting the sick and feeding the hungry. The pope last year declared 2016 to be the "Year of Mercy," and urged Catholics to meditate on how they could reflect the love of God in the world.

He tied environmental concerns to the growing global migrant crisis.

"Climate change is also contributing to the heart-rending refugee crisis," he said. "The world's poor, though least responsible for climate change, are the most vulnerable and already suffering its impact."

Catholics should use this year to reflect upon sins they may have committed against the environment, and also urged forgiveness for the "selfish" capitalist system which advocates "profit at any price."

"Economics and politics, society and culture cannot be dominated by thinking only of the short-term and immediate financial or electoral gains," the pope said. "Instead, they urgently need to be redirected to the common good, which includes sustainability and care for creation."

Pope Francis also targeted the indifference of many to environmental issues.

"We must not be indifferent or resigned to the loss of biodiversity and destruction of ecosystems, often caused by our irresponsible and selfish behavior," he said. "Because of us, thousands of species will no longer give glory to God by their very existence … We have no such right."

Pope Francis also called Earth "our common home," and said that rich nations have an "ecological debt" to poorer nations in the south.

"Repaying [this debt] would require treating the environments of poorer nations with care and providing the financial resources and technical assistance needed to help them deal with climate change and promote sustainable development," he said in the speech.

Finally, he called on Catholics to consider what kind of world they want to leave for the generations that comes after.

Cardinal Peter Turkson, president of the Vatican's council for peace and justice, also had commentary in the speech marking the church's World Day of Prayer.

"Pope Francis is asking us to be honest with ourselves and acknowledge that this is a sin—sin against creation, against the poor, against those who have not yet been born," Cardinal Turkson said.

"The first step in this process is to humbly acknowledge the harm we are doing to the earth through pollution, the scandalous destruction of ecosystems and loss of biodiversity, and the specter of climate change—which seems nearer and more dangerous with each passing year."

The pope is an "unlikely voice for the environment," The Guardian pointed out in an editorial comment. The pope has previously insisted, most notably in his encyclical released in 2015, that overpopulation is not a driver of environmental destruction.

Environmental protection is not taken seriously by a small minority of Catholics, who argue that increasing industrialization provides more jobs and keeps more people out of poverty, Catholic Online reported.

One scientist had criticized the pontiff when he raised ecological concerns last year. Speaking after Pope Francis' speech to the UN General Assembly in September 2015, renowned environmental scientist Paul Ehrlich criticized the Catholic Church for failing to preach the dangers of overpopulation and refusing to allow its congregants to practice family planning.

"The pope is dead wrong," Ehrlich said. "There is no competent scientist who would say that there is not a problem with population growth."

Pope Francis has made environmental consciousness one of his main focuses during his time in office. In 2015, he issued an encyclical—a teaching document—Laudato Si, which was the first ever to be issued that concerned the environment, Catholic.com reported. Also, encyclicals were traditionally addressed to bishops, and this one was the first to be addressed to every individual on the planet.

In it, the pope focused on pollution, climate change, water issues and the loss of biodiversity. He also linked these issues to global inequality.

In the encyclical, he called for human action: "Humanity is called to recognize the need for changes of lifestyle, production and consumption, in order to combat this warming or at least the human causes which produce or aggravate it."

Contrary to public belief, Pope Francis is not the first pope with an environmental message. His predecessor, Pope Benedict XVI, also was concerned about climate change, and listed pollution as a "new sin" in 2008, U.S. News & World Report said.