When Pope Francis releases his much-anticipated encyclical on the environment this week, he will find a largely receptive audience among American Catholics. Very few will have ever heard their own religious leaders speak about climate change before.

In a recent HuffPost/YouGov poll , 84 percent of U.S. Catholics -- and equal percentages of Protestants and agnostics/atheists -- said humans have a moral duty to protect the environment. Overall, 82 percent of Americans agreed.

But only 18 percent of Catholics in the YouGov poll said they had ever heard one of their own religious leaders speak about climate change. Just 20 percent of white Catholics said they had, compared to 70 percent of Hispanic Catholics, according to a recent study by the Public Religion Research Institute .

PRRI also reported that 73 percent of Hispanic Catholics and 53 percent of white Catholics said climate change is a major problem . Hispanic Catholics were over three times more likely than white Catholics -- 43 percent vs. 13 percent -- to believe theyd be personally impacted by climate change.

Even with the papal letter on the horizon, more than one-third of Catholics think religious leaders should avoid taking a stand on climate change, the YouGov poll found.

Pope Francis has repeatedly touched on the need to protect the environment and is expected to deliver the same message in this summers papal letter, which has been in the works for over a year .

In July 2014, the pope spoke about the exploitation of Earth for agricultural purposes during an address at the University of Molise in Italy. This is one of the greatest challenges of our time: to convert ourselves to a type of development that knows how to respect creation, he said.

As to the causes of climate change, just 52 percent of the general population and an equal share of Catholics said it was caused by humans, according to the YouGov survey. But 43 percent of Catholics said they would be more likely to take environmentally-friendly actions like recycling and saving water because of the popes encyclical. And 33 percent of British Catholics said essentially the same in a recent study conducted by Catholic aid agency Cafod.

Perhaps not surprisingly, the general American public was less likely to be influenced by the pope: Only 25 percent said they would act in more environmentally friendly ways after a papal encyclical.

Still, many have high expectations for the encyclical, as well as the popes upcoming address to the United Nations in September, said Neil Thorns, director of advocacy at Cafod. In an article for The Guardian, Thorns wrote :

The Catholic community everywhere will be called upon to reflect not just on whether our lifestyles are promoting care for creation, but whether our social, political and economic choices truly promote the interests of the poorest among us.

Graphics by Cameron Love/The Huffington Post.

The HuffPost/YouGov poll consisted of 1,000 completed interviews conducted May 22-27 among U.S. adults using a sample selected from YouGov's opt-in online panel to match the demographics and other characteristics of the adult U.S. population.

The Huffington Post has teamed up with YouGov to conduct daily opinion polls. You can learn more about this project and take part in YouGov's nationally representative opinion polling. Data from all HuffPost/YouGov polls can be found here . More details on the poll's methodology are available here .

Most surveys report a margin of error that represents some, but not all, potential survey errors. YouGov's reports include a model-based margin of error, which rests on a specific set of statistical assumptions about the selected sample, rather than the standard methodology for random probability sampling. If these assumptions are wrong, the model-based margin of error may also be inaccurate. Click here for a more detailed explanation of the model-based margin of error.