Political lines were drawn years ago, but the enthusiastic entry of a popular pope is changing the terms of the debate.
Pope Francis was the first to issue an environmentally conscious encyclical, or statement of doctrine, this summer.
The encyclical has caught many Catholic leaders by surprise. Many American bishops who have been firm on abortion and same-sex marriage have communicated the church's position on the environment less clearly.
"I think Francis would be disappointed by the lack of urgency in the response of most American bishops," Christopher Hale, director of Catholics in Alliance for the Common Good told the Guardian. "This isn’t just a letter to be read, but a call to be acted upon."
The conservative news site the Daily Caller describes the encyclical as advocating "eco-imperialism," that would hurt those in poorer countries. But an opinion piece for the Washington Post claims the pope's bold move into environmentalism will actually return the movement to its American roots. Mark Stoll, a professor at Texas Tech, wrote the movement began in conservative Calvinism and Presbyterianism, but environmentalists in the 1970s began to blame Christian theology itself for the problem.
"Recoiling, conservative Protestants called environmentalism pagan and anti-Christian," he wrote. "The divide helped create toady’s political impasse over global warming and other environmental issues."
Strong opinions of climate change by the leader of Christianity's largest sect can move the environmental discussion away from strictly secular grounds. American Catholics are divided on their views of climate change more by political affiliation than faith, according to a Pew Research Study from before the pope's encyclical was released. The study showed Catholics were more likely than Protestants, but less likely than atheists and agnostics, to believe climate change is a problem.
Villanova University, a Catholic college, is holding a public discussion Wednesday about the encyclical. Professors will share first impressions about the call to action on climate change by the pope, according to a statement.
From the secular side, environmental scientists and scholars speculated in a Yale online forum as to what the pope might say – and what they wanted him to say – about climate change in his Sept. 25 speech at the United Nations.
"I think the pope has already done more than anyone could possibly ask: beautifully framed climate change for what it is, which is less an ‘environmental issue’ than an existential problem requiring a new/old way of looking at the planet," said Bill McKibben of Middlebury College as part of the Yale forum.
A fellow from Worldwatch Institute, Robert Engelman, said a change in Catholic doctrine would best serve the environment. He said he hopes the Pope Francis will reverse the Catholic ban on contraception. "The pope could at least acknowledge that his much-noted respect for science failed him when he dismissed reductions in birth rates as helpful to the preservation of climate," he said in the online forum.