Dumping plastic in waterways is "criminal" and must end if humanity wants to save the planet for future generations, Pope Francis said in a television interview on Sunday.
In the hour-long interview on state broadcaster RAI's Channel 3, Francis also reiterated some of the key themes of his papacy, condemning excessive spending on armaments, defending the rights of migrants, and condemning ideological rigidity by conservatives in the Church.
Francis, who has made defending the environment a cornerstone of his pontificate, recounted how Italian fishermen came to him one year and told him they had found many tons of plastic in the Adriatic Sea. The next time he saw them they said they had found twice as much and took it upon themselves to help clean some of it up.
"Throwing plastic into the sea is criminal. It kills biodiversity, it kills the earth, it kills everything," he said."
"Looking after creation is an education (process) in which we must engage," he said, citing a song by Brazilian singer Roberto Carlos in which a boy asks his father why "the river no longer sings" and the father responds that "we finished it off".
Asked to elaborate on his taste in music, Francis, who made a surprise visit to a Rome record store last month, said he mostly likes classical music but also tango.
Asked if he had danced the tango as a young man in his native Argentina, Francis, 85, said "A porteño who does not dance the tango is not a porteño". Porteño is the Spanish name for a resident of Buenos Aires, his home city.
In response to a question about war, Francis said: "Think about it. If we were to stop making weapons for one year, we could feed and educate the whole world. We have become accustomed to wars. It's tough but it's the truth."
Francis did not elaborate on the source of the statistics he cited but in the past he has called for a total ban on nuclear weapons, saying even their mere possession for deterrence is immoral.
He also has called for armaments spending to be diverted to help the neediest and for research to prevent future pandemics.
Francis again called on the European Union to distribute migrants reaching Italy and Spain from North Africa to all EU countries so as not to put excessive social strain on a few countries.
The interview with the host of the popular Sunday programme Che Tempo Che Fa (What's the Weather Like?) was conducted via a satellite link from RAI studios in Milan with the Santa Marta residence in the Vatican where the pope lives.
Francis has shunned the spacious but insulated papal apartments in the Vatican's Apostolic Palace used by his predecessors. He lives in modest suite in Santa Marta, where he usually eats in the common area and takes the elevator by himself.
Francis said he had chosen to live there because he was "not a saint" like his predecessors and needed to be around people as much as possible. He said he had "few but real" friends.
(Reporting by Philip Pullella; Editing by Lincoln Feast.)