Pope Francis, leader of the world’s 1.2 billion Catholics, could have an influential role in this December’s negotiations for a climate agreement and is expected to issue a call for action to address the problem this year, observers and Senate Democrats said.

Those predictions come shortly after a senior Vatican official, who helped write the first draft of Pope Francis’s expected encyclical on the environment, outlined several key themes expected in the upcoming document, expected to be released this summer.

The pope’s views, possibly expounding upon climate change, will again take center stage in September when he will travel to the U.S. and address a joint session of Congress and the UN General Assembly.

Cardinal Peter Turkson, head of the Pontifical Council for Justice and Peace, said the pope won’t make a political statement on climate change but instead will emphasize ancient church teaching that core components of life include fighting inequality and protecting the environment.

While international agreements on climate are important, Turkson said, a “changing of human hearts” is necessary to adequately fight the problem on a global scale.

Duty to Care for Creation

Turkson, speaking March 5 in Ireland, acknowledged lingering disagreement over the role of human activity in climate change. But “what is not contested is that our planet is getting warmer,” and Christians have a duty to address the problem, he said.

“Even the compelling consensus of over 800 scientists of the Intergovernmental Panel on Climate Change will have its critics and its challengers,” Turkson said. “For Pope Francis, however, this is not the point. For the Christian, to care for God’s ongoing work of creation is a duty, irrespective of the causes of climate change.”

Francis himself in January said climate change is “mostly” due to the actions of humans and criticized United Nations negotiators for a “lack of courage” to address the problem.

The pope expressed hope that negotiators would be “more courageous” when they meet Nov. 30—Dec. 11 in Paris with the goal of reaching an international climate accord.

Unique Influence Seen

Those closely monitoring the climate negotiations and some senators told Bloomberg BNA in interviews March 11-13 that the pope would bring a significant moral influence to the discussions that could help boost the odds of reaching a final agreement.

“Few individuals wield a megaphone as big as the pope’s,” Elliot Diringer, who tracks the negotiations as executive vice president for the Center for Climate and Energy Solutions, said. “He can introduce a genuine moral dimension into a debate that otherwise is far too ideologically driven.”

“We typically make the case based on science, but when science and religion are pointing in the same direction, that can be a powerful signal,” Diringer added.

Even coal and several conservative organizations acknowledged to Bloomberg BNA that the pope could have a major impact on the negotiations through his encyclical and other speeches, but they said Francis should consider scientific work that does not back the consensus that human activity significantly contributes to climate change and should weigh the impact climate policies could have on many of world’s poorest people.

Others expect Pope Francis to help raise public awareness about the issue of climate change and tout the issue to a worldwide audience due to his popularity across various religious groups.

“Will it transform the discussion and lead to a totally different outcome? Maybe not, but it will bolster the chances of an agreement in Paris and boost the urgency world leaders feel,” Alden Meyer, director of policy and strategy for the Union of Concerned Scientists, said. “It will have a pretty big impact.”

The encyclical, in particular, could have a profound impact on certain world leaders and lead to greater engagement at the negotiations, others said.

“The pope can touch hearts and minds in ways that few others can—by connecting with people on a personal, moral level,” Jennifer Morgan, global director for the World Resources Institute’s climate program, told Bloomberg BNA in a statement. “His encyclical on climate change could prompt some leaders to engage more productively in the lead up to the Paris climate negotiations.”

Vatican Has ‘Observer State’ Status

While not a formal party to the negotiations, the Holy See holds the status of an “observer state” to the talks held under the UN Framework Convention on Climate Change.

Several Senate Democrats told Bloomberg BNA the pope’s leadership on climate issues would be helpful to the negotiations in Paris.

“I think the pope’s statements are going to bring a moral weight to the whole process,” Sen. Ed Markey (D-Mass.), who has been closely watching progress toward an international agreement, said. “It’s very hard to overstate its importance.”

Francis also has the unique ability—as the head of a major religion and head of state for the Vatican—to speak to “what most people believe is the moral compass of our globe” in both religious and governmental terms, Sen. Ben Cardin (D-Md.) said.

“It’s a very effective voice because I think most people recognize it’s rooted beyond the interests of one country,” Cardin said. “He really can bridge his religious standing with his standing as the head of the Vatican. I think he can get a much broader audience than just a head of state.”

Anticipation of Congressional Visit

Americans are likely to hear more from the pope about the need for addressing climate change when he visits the U.S. in September. Francis plans to deliver the first-ever address by a pope before a joint session of Congress Sept. 24.

Another Democrat aggressively seeking global action on climate change, Sen. Sheldon Whitehouse (D-R.I.), said Francis could play a “huge role” in the talks through publication of his encyclical and addressing Congress this fall.

“I think the encyclical is potentially historic,” Whitehouse said. “I think his speech to the joint session of Congress in September could be a tipping point. His standing throughout Europe is such that he could be a real presence in Paris.”

Several of those following the talks said Francis has been working behind the scenes to reach out to leaders of different faiths, perhaps in hopes of issuing a joint statement or declaration ahead of the Paris negotiations.

“If they’re able to do something across faiths, that would also be very powerful,” Meyer said.

A State Department official declined to speculate about the content or impact of the pope’s forthcoming encyclical but said the department is “encouraged to see broad participation from all sectors in ensuring strong global action to address the threat of climate change.”

Elevating Issue of Climate Change

Both of the pope’s immediate predecessors—Popes John Paul II and Benedict XVI—spoke out more generally in favor of environmental protection, but Francis is the first to elevate the issue of climate change to such prominence.

Encyclicals such as the one Francis will soon issue on the environment are among the strongest papal statements and usually reserved for important Catholic teachings.

Many expect Francis to devote a portion of his address to Congress to climate change, even though most Republicans in the House and Senate don’t agree with the scientific consensus that human activity significantly contributes to climate change.

“It is hard for me to imagine that he wouldn’t bring this in” to his speech before Congress, Meyer said.

Conservatives Urge Open Mind

Coal industry and several conservative groups told Bloomberg BNA they hoped Pope Francis would keep an open mind to the impact climate policies could have on poor communities throughout the world, but acknowledged his potential influence on the topic.

“I actually believe it is appropriate for the pope to speak on this, but I think his message should be the appropriate message,” H. Sterling Burnett, a research fellow on energy and environmental issues with the Heartland Institute, told Bloomberg BNA. “He needs to take account of the harms to people if they restrict access to fossil fuels…I don’t believe the pope will change any minds, but he could reinforce existing positions.”

The American Coalition for Clean Coal Electricity, a coal industry trade group, said coal was the only fuel source that could lift emerging economies out of poverty.

“While we certainly respect the views of the Pope, we too believe we’re on the side of Angels as we consider the plight of billions of people around the globe who are living without electrification and suffering though untold poverty and disease as a result,” Laura Sheehan, senior vice president of communications for the group, said. “We believe we must work together with policymakers and social leaders – like Pope Francis – to support policies that bring about new advances in clean coal technologies so that we can strike a balance between economic and climate needs.”

The offices of several Republican senators—Sens. John Barrasso (Wyo.) and James Inhofe (Okla.)—declined to comment on the pope’s involvement in climate issues.

Benjamin Zycher, a resident scholar at the American Enterprise Institute, said spiritual leaders should in general avoid highly political issues but said the pope’s ideas should ultimately be judged for their analytical rigor.

Caution Over Political Topics

“We’ll have to see what he says, but as a general proposition I would advise spiritual leaders to avoid topics that are highly charged politically and not closely related to doctrinal interpretations,” Zycher said. “There will be also an obvious tension between any advocacy of action on climate policy and the long-term concern of the Church for the economic wellbeing of many millions of people less fortunate. The environment left will deny this, but that is sophistry that I hope Francis will not endorse.”

Several conservatives have more bluntly criticized Pope Francis for his statements on climate change and for his embrace of what they call a “radical left” agenda.

“Pope Francis—and I say this as a Catholic—is a complete disaster when it comes to his policy pronouncements,” Stephen Moore, chief economist for the Heritage Foundation, wrote in a January op-ed. “On the economy, and now on the environment, the pope has allied himself with the far left and has embraced an ideology that would make people poorer and less free.”

Despite the perception by some that the pope is taking sides in a contentious political issue, Cardinal Turkson said Pope Francis was merely reiterating ancient church teachings as the world enters the critical period leading up to a potential climate agreement.

“The coming 10 months are crucial, then, for decisions about international development, human flourishing and care for the common home we call planet Earth,” Turkson said. “As we confront the threat of environmental catastrophe on a global scale, I am confident that a shaft of light will break through the heavy clouds and bring us what Pope Francis describes as the warmth of hope.”