This coming Thursday, Pope Francis will deliver his much anticipated papal encyclical. For those not up on their papal-what nots, an encyclical is essentially a teaching letter that is either shared with religious leaders or a wider audience. In this case, it’s the latter.

So what’s all the ruckus? This encyclical will be the first to address climate change and the need for environmental protection.

Addressing a crowd at St. Peter’s on Sunday, the pope said he hoped the document would spark "renewed attention to situations of environmental degradation and to recovery" and lead to "greater responsibility for the common home that God has entrusted to us".

Catholic or not, this is something everyone can get behind.

According to people familiar with the document, the encyclical will touch on subjects we address frequently on Global Citizen such as the impact that climate change is having on the world’s poor, wealth inequality, and population growth. Wealthy countries, they say, will be asked to act more sustainably by re-examining throw-away lifestyles.

Another key message will be that man is responsible (at least in part) for the changes we’re seeing in the planet.

"I don't know if it is all (man's fault) but the majority is, for the most part, it is man who continuously slaps down nature," the pope said in January. "I think man has gone too far ... thank God that today there are voices that are speaking out about this."

It’s worth noting that while a papal encyclical is authoritative, it’s not considered infallible.

John Cavadini, professor of theology and director of the Institute for Church Life at the University of Notre Dame in the United States, explains:

"He doesn’t thereby canonize or dogmatize a scientific theory, which by its very nature is subject to falsification and revision. But it is within the pope’s competence and authority to call attention to our moral responsibilities and duties in the face of the best scientific theory out there, especially when the consequences of not doing so are serious or even drastic, and where silence could be interpreted as scandalous.”

Infallible or not, with an audience of 1.2 billion Catholics (not to mention the pope’s other supporters) this document is a huge opportunity to build support for climate mitigation and environmentally sustainable policies. And just in time too, with the UN Summit on Climate Change in December.

Way to go Pope Francis for speaking out on this important issue!