VATICAN CITY (CBS/AP) — Pope Francis warned the rich and powerful on Tuesday that God will judge them on whether they fed the poor and cared for the Earth, his latest exhortation on the environment ahead of his eagerly-awaited encyclical on climate change and its effects on the world’s most vulnerable.

Francis delivered the warning during a Mass for the Vatican’s Caritas Internationalis charity.

In his homily, Francis said the planet has enough food to feed the world but “it seems that there is a lack of willingness to share it with everyone.”

“We must do what we can so that everyone has something to eat. But we must also remind the powerful of the Earth that God will call them to judgment one day,” he said. “And there it will be revealed if they really tried to provide for him in every person, and if they did what they could to preserve the environment so that it could produce this food.”

ALSO READ: San Francisco Bay Area Least ‘Church Going’ Metro In America

No papal document in recent times has produced as much anticipation or anxiety as Francis’ encyclical, which is expected next month. Environmentalists are thrilled that Francis is lending his moral authority to provide an ethical foundation for action to stem climate change. Conservatives, including many Christians, have criticized Francis for wading into the politically charged climate debate.

On Tuesday, one of Francis’ key advisers, Cardinal Oscar Rodriguez Maradiaga, said he was stunned by the complaints he had heard during a trip to the United States over a papal document that hasn’t even been published yet. He accused those fueling it of an ideology “that is very strongly linked to a vision of capitalism that doesn’t want to renounce damaging the environment for the sake of profits.”

Francis has said global warming is “mostly” man-made and that humanity has a moral duty to stop it.

Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.