Donald Trump’s denial of climate change has made him an adversary of environmentalists — a group that includes the world’s most revered religious leader.

In an address to a group of scientists at the Vatican this week, Pope Francis suggested science has become more important than ever.

“Never before has there been such a clear need for science to be at the service of a new global ecological equilibrium,” the pope said, adding that the goals of the scientific and Christian communities are increasingly converging around the need to protect the planet. These sentiments echoed those more elaborately described in the pope’s encyclical on the environment, which was published in June 2015.

The delegation of 80 scientists — called the Pontifical Academy of Sciences — includes physicist Stephen Hawking as well as Nobel laureates in the fields of chemistry, physics and medicine.

Though Pope Francis never mentioned Donald Trump by name, he suggested that the delay in implementing global climate agreements indicates that politics has submitted to the profit motive.

“It is worth noting that international politics has reacted weakly – albeit with some praiseworthy exceptions – regarding the concrete will to seek the common good and universal goods, and the ease with which well-founded scientific opinion about the state of our planet is disregarded,” the pontiff said.

Trump stated in 2012 that global warming was a hoax created by the Chinese to make the US business and manufacturing sectors less competitive. Although he recently told the New York Times that there is “some connectivity” between humans and climate change, his future chief of staff, Reince Priebus, later told Fox News that Trump’s default position is that climate science is “a bunch of bunk.”

President-elect Donald Trump addresses the crowd at his election night party in New York. Mark Wilson/Getty Images Trump’s campaign promises included pulling the US out of the landmark Paris climate accord, which commits 115 countries to work together to keep the global temperature from rising more than 2 degrees Celsius.

Without the US, the global greenhouse gas emissions reductions would be weaker, and less money would be available for developing countries to use in their climate efforts (the agreement established a fund with contributions from rich nations). Leaders including Xie Zhenhua, China’s top climate negotiator, have criticized Trump for his threat to back out, and vowed to continue the work with or without the US.

Even without pulling out of the agreement, however, Trump could simply take advantage of the fact that it has no mechanisms of enforcement beyond requirements for transparency, and do nothing to regulate or decrease US emissions. That too, the pontiff said, is unacceptable.

“We are not custodians of a museum or of its major artifacts to be dusted each day, but rather co-operators in protecting and developing the life and biodiversity of the planet and of human life present there,” Pope Francis said.

Neither Trump nor Myron Ebell, who is leading the Environmental Protection Agency transition, share that philosophy. Ebell has suggested that climate research is actually an arm of a coordinated political movement, and told Business Insider in August that environmental issues are best resolved by innovation in the free market. “It would be much better to free up the economy and get rid of the EPA rules and a lot of the Department of Energy programs,” he said.

Bob Walker, a senior Trump advisor, has also suggested that the administration will strip funding from NASA’s earth science research. The cut, Walker told the Guardian, is part of an effort to eliminate “politicized science” and prioritize deep space research. But the pope also suggested the nature of scientific research and consensus means it doesn’t have an agenda.

“It falls to scientists, who work free of political, economic or ideological interests, to develop a cultural model which can face the crisis of climatic change and its social consequences,” the pontiff said.

Environmentalists are already prepared for a future full of showdowns with Trump.

“If Trump does try to undermine climate action, he will run headlong into an organized mass of people who will fight him in the courts, in the states, in the marketplace and in the streets,” Michael Brune, executive Director of the Sierra Club wrote in a statement following the election.

It seems those advocates will have the pope on their side.