Pope Benedict was accused of stoking homophobia today after a speech in which he declared that saving humanity from homosexuality was just as important as saving the rainforest from destruction.

The Pontiff made the remarks yesterday in an end-of-year address to the Curia, the Vatican's central administration. He said that humanity needed to listen to the “language of creation” to understand the intended roles of man and woman and behavior beyond traditional heterosexual relations was a “destruction of God’s work”.

“The tropical forests do deserve our protection. But man, as a creature, does not deserve any less," Benedict told scores of prelates gathered in the Vatican's Clementine Hall.

"What’s needed is something like a ‘human ecology,’ understood in the right sense. It’s not simply an outdated metaphysics if the Church speaks of the nature of the human person as man and woman, and asks that this order of creation be respected.”

It is not the first time that Benedict has used the Curia speech to throw out a controversial idea – two years ago he complained that Islam had yet to learn the lessons of the Enlightenment – but the comments were quickly denounced by gay and lesbian groups, both inside and outside the Church.

The Rev Sharon Ferguson, chief executive of the Lesbian and Gay Christian Movement, described Benedict's comments as “totally irresponsible and unacceptable in any shape or form.”

She said: “It is more the case that we need to be saved from his comments. It is comments like that that justify homophobic bullying that goes on in schools and it is comments like that that justify gay-bashing.

“There are still so many instances of people being killed around the world, including in Western society, purely and simply because of their sexual orientation or their gender identity.

“When you have religious leaders like that making that sort of statement then followers feel they are justified in behaving in an aggressive and violent way because they feel that they are doing God’s work in ridding the world of these people.”

Pam Spaulding, a leading lesbian blogger from the U.S., was even more direct: "The Prada Papa Ratzi opens his trap again, and the homophobia stinks like trash piled up during a NYC garbage strike."

The Catholic Church teaches that while homosexuality is not sinful, homosexual acts are. It opposes gay marriage and, in October, a leading Vatican official called homosexuality “a deviation, an irregularity, a wound”.

Benedict's speech was also seen, however, as a denunciation of "gender theory" – the study of how gender assignments affects the behaviour of individuals. The Catholic Church has repeatedly spoken out against gender theory, which gay and transsexual groups promote as a key to understanding and tolerance.

“That which is often expressed and understood by the term ‘gender’ in the end amounts to the self-emancipation of the human person from creation and from the Creator," the Pope said.

"Human beings want to do everything by themselves, and to control exclusively everything that regards them. But in this way, the human person lives against the truth, against the Creator Spirit.”