ROME (AP) — Pope Leo XIV took aim Wednesday at skeptics who “ridicule those who speak of global warming,” as he strongly embraced Pope Francis’ environmental legacy and made it his own in some of his strongest and most extensive comments to date.

Leo presided over the 10th anniversary celebration of Francis’ landmark ecological encyclical, Laudato Si (Praised Be) at a global gathering south of Rome. The encyclical cast care for the planet as an urgent and existential moral concern and launched a global grassroots movement to advocate for caring for God’s creation and the peoples most harmed by its exploitation.

Leo told the estimated 1,000 representatives from environmental and indigenous groups that they needed to pressure national governments to develop tougher standards to mitigate the damage already done. He said he hoped the upcoming U.N. climate conference “will listen to the cry of the Earth and the cry of the poor.”

He didn’t name names, but history’s first American pope spoke just days after U.S. President Donald Trump complained, with false statements, to the U.N. General Assembly about the “con job” of global warming. Trump has long been a critic of climate science and polices aimed at helping the world transition to green energies like wind and solar power.

Leo quoted Francis’ follow-up encyclical, published in 2023, in which the Argentine pope shamed and challenged world leaders ahead of a U.N. conference to commit to binding targets to slow climate change before it’s too late.

Citing Francis’ text, Leo recalled that some leaders had chosen to “deride the evident signs of climate change, to ridicule those who speak of global warming and even to blame the poor for the very thing that affects them most.”

Leo called for a change of heart to truly embrace the environmental cause and said any Christian should be on board.

“We cannot love God, whom we cannot see, while despising his creatures. Nor can we call ourselves disciples of Jesus Christ without participating in his outlook on creation and his care for all that is fragile and wounded,” he said, presiding on a stage that featured a huge hunk of a melting glacier from Greenland and tropical ferns.

Leo has strongly taken up Francis’ ecological mantle, giving his blessing to a Vatican plan to turn an agricultural field north of Rome into a vast solar farm. Once it is up and running, the farm is expected to make the Vatican City the world’s first carbon-neutral state.