Vatican City, June 20 (RHC)-- The Vatican has unveiled Pope Francis’ historic encyclical on climate change, urging world leaders to pay their "grave social debt" to the poor and take swift action to save the planet from environmental ruin.

Pope Francis calls for a change of lifestyle in rich countries steeped in a "throwaway" consumer culture, and an end to "obstructionist attitudes" that sometimes put profit before the common good.

In a nearly, 200-page document, the Pope writes: "Climate change is a global problem with grave implications: environmental, social, economic, political and for the distribution of goods. It represents one of the principal challenges facing humanity in our day."

Presenting the encyclical, a Vatican official said it should encourage the merging of environmental consciousness with spiritual teachings.