In his newly released encyclical on the environment, Pope Francis did not hesitate to wade into controversial topics, making statements on global warming, pollution, species extinction and global inequality's impact on natural resources.

"A very solid scientific consensus indicates that we are presently witnessing a disturbing warming of the climatic system," the Pope said in his new encyclical "Laudato Si."

He cited "a constant rise in the sea level" and an apparent increase in extreme weather events.

"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."

While acknowledging other factors behind global warming, the encyclical said that a number of scientific studies indicate that "most global warming in recent decades is due to the great concentration of greenhouse gases…released mainly as a result of human activity."

Pope Francis' second encyclical was released June 18. Its title is taken from Saint Francis of Assisi's "Canticle of the Sun," which reflects on the Earth as a sister and mother.

"This sister now cries out to us because of the harm we have inflicted on her by our irresponsible use and abuse of the goods with which God has endowed her. We have come to see ourselves as her lords and masters, entitled to plunder her at will," he said. "The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life."

In his typical fashion, the Pope did not shy away from controversial issues. He cited studies supporting the theory of global warming and stated that human activity is the primary driving force behind the phenomenon, as well as the main cause of species extinction. He also spoke of developed nations' obligations involving renewable resources and the development of poorer countries.

Saying that the earth "is beginning to look more and more like an immense pile of filth," the encyclical states, "Never have we so hurt and mistreated our common home as we have in the last two hundred years."

The Pope lamented that "(f)requently no measures are taken (to address industrial waste and chemical byproducts) until after people's health has been irreversibly affected."

He connected the problem of waste to a "throwaway culture," saying that the industrial cycle of production and consumption "has not developed the capacity to absorb and reuse waste and byproducts."

In contrast to the "exemplary" workings of natural ecosystems, he said, "(w)e have not yet managed to adopt a circular model of production capable of preserving resources for present and future generations, while limiting as much as possible the use of non-renewable resources, moderating their consumption, maximizing their efficient use, reusing and recycling them."

Pope Francis said it is urgent to develop policies and programs so that emissions of carbon dioxide and other polluting gases can be "drastically reduced," such as by substituting sources of renewable energy for fossil fuel use.

The Pope's encyclical reflected on the depletion of natural resources in the context of local and global inequality.

"We all know that it is not possible to sustain the present level of consumption in developed countries and wealthier sectors of society, where the habit of wasting and discarding has reached unprecedented levels. The exploitation of the planet has already exceeded acceptable limits and we still have not solved the problem of poverty," he said.

The resources of the earth are "being plundered because of short-sighted approaches to the economy, commerce and production."

The encyclical said that developing countries fuel richer countries' development "at the cost of their own present and future."

"The land of the southern poor is rich and mostly unpolluted, yet access to ownership of goods and resources for meeting vital needs is inhibited by a system of commercial relations and ownership which is structurally perverse."

Developed countries ought to significantly limit their consumption of non-renewable energy and assist poorer countries' support for sustainable development policies and programs, the document said.

"It is remarkable how weak international political responses have been," the Pope remarked, attributing the failure of global environmental summits to the subjection of politics to "technology and finance."

"There are too many special interests, and economic interests easily end up trumping the common good and manipulating information so that their own plans will not be affected," he said.

The Pope also spoke on behalf of the world's animal and plant life. Habitat loss, he said, "entails the loss of species which may constitute extremely important resources in the future."

"Each year sees the disappearance of thousands of plant and animal species which we will never know, which our children will never see, because they have been lost forever."

The encyclical attributed the "great majority" of these extinctions to human activity.

"Because of us, thousands of species will no longer give glory to God by their very existence, nor convey their message to us. We have no such right," it said.

The Pope's encyclical acknowledged that there are some environmental issues "where it is not easy to achieve a broad consensus."

"Here I would state once more that the Church does not presume to settle scientific questions or to replace politics," Pope Francis said. "But I am concerned to encourage an honest and open debate so that particular interests or ideologies will not prejudice the common good."