Pope Francis on Thursday put forth an urgent call for people to actively work to save the environment, proposing that the Catholic Church add such a duty to the list of "seven mercies," which includes feeding the hungry and visiting the sick, which Catholics are required to perform.

"We must not be indifferent or resigned to the loss of biodiversity and the destruction of ecosystems, often caused by our irresponsible and selfish behaviour."

—Pope Francis"Francis described man's destruction of the environment as a sin," the Guardian reported.

"The modern world has new forms of poverty, Francis said, and thus requires new forms of mercy to address them," the Washington Post noted.

In his speech to mark the church's World Day of Prayer for the Care of Creation, which the pope created last year, Francis accused humans of turning the Earth into a "polluted wasteland full of debris, desolation, and filth."

Remarking on the planet's rapid warming, Francis observed that "[c]limate change is also contributing to the heart-rending refugee crisis. The world's poor, though least responsible for climate change, are most vulnerable and already suffering its impact."

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

"We have no such right," Francis said.

Francis' speech built on ideas he first put forth last year in Laudato Si, his unprecedented encyclical on climate change and environmental protection.

Earlier this month, Francis also excoriated capitalism for leading to endless war.