Pope Francis' new encyclical titled "Laudato Si (Be Praised), On the Care of Our Common Home", is displayed during the presentation news conference at the Vatican on June 18, 2015. Photo courtesy of REUTERS/Max Rossi
*Editors: This photo may only be republished with RNS-ENCYCLICAL-FUTURE, originally transmitted on June 18, 2015, and with RNS-POPE-ARRIVE, originally transmitted on Sept. 22, 2015.
(RNS) Pope Francis’ landmark document on protecting the environment and battling climate change is finally out after months of anticipation -- and anxiety -- that in the history of encyclicals is probably rivaled only by Pope Paul VI’s 1968 letter banning artificial birth control. But will it have an effect? Here are four challenges Francis faces going forward.