As the one-year anniversary of Pope Francis’ eco-encyclical Laudato Si’ approaches, new research shows that Catholics in the United States are more likely than other Christians to accept global warming and to believe they have a responsibility to combat it, though how much credit the pope can claim for that is unclear.

The results come from a survey conducted by the Center for Applied Research in the Apostolate at Georgetown University, which took place in May.

According to the poll results, 63 percent of Americans overall agree that temperatures on Earth are becoming warmer because of a concentration of greenhouse gases. Among Catholics that figure is 65 percent, while among Evangelicals the share  drops to 51 percent.

More or less in keeping with the overall share of Americans, 68 percent of U.S. Catholics believe that the increasing concentration of greenhouse gases is largely due to human activity, while only 59 percent of Evangelicals believe that’s the case.

In general, Americans with a non-Christian affiliation or no religious affiliation are even more likely to concur with both the warming trend and its causation by human activity.

However, it’s not clear that the pontiff’s encyclical has had much impact on American attitudes.

In July 2015, shortly after the release of Laudato Si’, only 31 percent of Americans said they had even heard of it, and the CARA poll found that percentage has fallen a few percentage points over time. Only 32 percent of Catholics in the recent survey remembered hearing of the encyclical, and majorities of all groups said they don’t recall hearing or reading about the document.

On the other hand, support for the idea that global warming is real and that it’s caused by human activity are about 15 percentage points higher among those Americans who are aware of the pope’s document.

Overall, 22 percent of Americans say they agree with the pope on the environment against 19 percent who say they don’t, while most said they don’t know. Among Catholics, those in agreement were 34 percent, those against 15 percent, and more than half said they didn’t know.

Strikingly, the percentage of U.S. Catholics who say they believe God plays a role in climate change is lower than the general population, 22 percent to 17. That’s likely explained by the fact that 46 percent of American Evangelicals said they agree with the statement.

In general, 66 percent of U.S. Catholics and 60 percent of Americans generally said they believe climate change is either the “most important” problem facing the world or “very important.”

On the question of whether they have a personal responsibility to combat climate change, 68 percent of Catholics and 63 percent of Americans generally agreed, with those who reported recalling the pope’s encyclical more likely to agree.

Some 32 percent of Catholics said the pope’s statements had affected that belief, but they were less likely to credit pastors, bishops, or any other person in Church ministry with any impact on their attitudes.

Interestingly, the survey found that 77 percent of Americans with no religious affiliation believe that society should take steps to combat climate change, and 95 percent who have heard of Francis’s encyclical take that view.

“The data may indicate that Pope Francis has strengthened the case that individuals and society have a moral responsibility to act against climate change among those who are among the least religious in the United States,” a CARA blog states.

Although Francis is hardly the first pope to address the issue of ecological responsibility and environmental protection, since both St. John Paul II and emeritus Pope Benedict XVI addressed those issues repeatedly, the survey also suggests that many Americans are unaware of those precedents.

It found that 32 percent of Americans generally believe Francis is the first in the Church to address climate change, and, surprisingly, the percentage who believe that to be the case is even higher among Catholics at 42 percent.

The complete report can be found here.