Pope Francis is considering introducing 'ecological sins' in a new bid to battle climate change. Pictured: The Pope in Vatican City today

Pope Francis is considering introducing 'ecological sins' in a new bid to battle climate change.

Speaking in Rome on Friday, Pope Francis said it's 'a duty' to introduce the new sin to the Catholic Church's teachings as a way to protect 'our common home'.

This comes after the Pope held a three-week bishops' assembly, called a synod, last month which addressed environmental dangers in the Amazon.

Speaking on Friday, he said: 'We have to introduce, we are thinking about it, in the catechism of the Catholic Church, the sin against ecology, the sin against our common home, because it’s a duty.'

He was addressing members of the International Association of Penal Law in Rome, Crux Now reports.

At the same event, the pope also said that politicians who rage against homosexuals, gypsies and Jews remind him of Hitler.

'It is not coincidental that at times there is a resurgence of symbols typical of Nazism,' Francis said in an address to participants of an international conference on criminal law.

Speaking in Rome on Friday, Pope Francis said it's 'a duty' to introduce the new sin to the Catholic Church's teachings as a way to protect 'our common home'. Pictured: Pope Francis poses for a picture with a youth patient after meeting members of the Bambino Gesu (Baby Jesus) hospital

'And I must confess to you that when I hear a speech someone responsible for order or for a government, I think of speeches by Hitler in 1934, 1936,' he said, departing from his prepared address.

'With the persecution of Jews, gypsies, and people with homosexual tendencies, today these actions are typical (and) represent ''par excellence'' a culture of waste and hate. That is what was done in those days and today it is happening again.'

During the 1933-45 Nazi regime in Germany, six million Jews were killed and homosexuals and gypsies were among those sent to extermination camps.

Pope Francis did not name any politicians or countries as the targets of his criticism.

In Brazil, President Jair Bolsonaro had a history of making homophobic, racist and sexist public remarks before he took office on January 1. He told one interviewer he would rather have a dead son than a gay son.