Catholic leaders have long held that the environment is a part of the creation of God, and God's people have a responsibility to protect it. For instance, the United States Conference of Catholic Bishops issued a statement about global warming and global climate change in 2001 emphasizing concern for the environment. However, in 2015 Pope Francis issued a definitive encyclical of over 40,000 words called Laudato Si, meaning "praise be to you" or "be praised," which was devoted solely to the issue of the environment. A papal encyclical carries the weight of papal authority, and it is supposed to be taken with the utmost seriousness by members of the Catholic Church. This encyclical was fairly unique in that it was not addressed to specific leaders within the church, or even to Catholics only, but to all the people of Earth.
A team of scientists and theologians prepared the encyclical at the pope's orders. He asked the scientists to only include "the things that are clear and that are proven and not hypotheses, the realities." He then called another team of theologians and philosophers to reflect upon it and make suggestions. Finally, the pope himself edited it.
The encyclical begins by describing numerous environmental problems that the world is facing such as pollution, climate change, the availability of clean water, the loss of biodiversity, the breakdown of society, the lessening of the quality of human life, and inequality. The pope calls for changes in production, consumption, and lifestyle to combat global warming. Although the encyclical deals in part with scientific issues, because the pope relates those issues to faith and morality, Catholics are unable to dismiss what the pope says, even if their political beliefs cause them to disagree with some parts of the encyclical.
Church leaders who helped to draft the encyclical acknowledged that some of the issues it raises are controversial, but they emphasized that it was the pope's wish that bringing these things out into the open would stimulate debate on how the environment could best be protected for present and future generations. People who are environmentally conscious but not religious can see common cause in the pope's statements, while conscientious Catholics who did not previously care about the environment can see it as an authoritative call to action.