"I hope I'm not going to get castigated for saying this by my priest back home," Bush said. "But I don't get my economic policy from my bishops or my cardinals or my pope."
Bush, a former Florida governor who converted to Catholicism 25 years ago, said religion "ought to be about making us better as people and less about things that end up getting into the political realm."
Francis, according to a leaked draft version of his encyclical, or a letter to bishops, says the world could see destruction of entire ecosystems this century without urgent action on climate change.
In the Italian version of the 192-page document, posted on Monday (June 15) by the weekly magazine l'Espresso, the pope again backs scientists who say global warming is mostly man-made and says that developed countries have a particular responsibility to stem a trend that will hurt the poor the most.
More than 70 percent of US Catholics believe the planet is getting warmer, though only 47 percent attribute that warming to human causes, according to the Pew Research Center. The views of Catholics on the issue are similar to those of Americans overall.