A change in people's lifestyles and energy consumption is needed to avert the "unprecedented destruction of the ecosystem" that can cause "grave consequence" to every inhabitant of the Earth.

This is what Pope Francis will say in the encyclical letter he is set to send to around 5,000 Catholic bishops all over the world this Thursday, June 18, based on a draft of the much-awaited papal letter that was leaked by an Italian magazine on Monday.

According to the Guardian, L'Espresso magazine revealed that the Pope will also ask for the creation of a new global political authority, which he said should be in charge of initiating discussions on how to reduce pollution and help poor countries and regions develop.

"Humanity is called to take note of the need for changes in lifestyle and changes in methods of production and consumption to combat this warning, or at least the human causes that produce and accentuate it," the Pontiff said, according to the Guardian.

"Numerous scientific studies indicate that the greater part of the global warming in recent decades is due to the great concentration of greenhouse gases ... given off above all because of human activity," he was quoted as saying in the leaked document.

Citing the Italian magazine, the Guardian noted that the Argentinian pontiff is also expected to single out climate-change deniers who, he said, continue to obstruct solution to the world's problem on greenhouse gasses.

The Pontiff is hoping his remarks would influence Republicans in the United States, who continue to deny climate change as a man-made phenomenon as they oppose regulatory efforts made by the Obama administration in Washington, the Catholic News Agency said, citing its sources.

The leak of the encyclical letter, which is titled "Laudato Si" or "Praised Be You," has frustrated Vatican officials, who planned its release before Pope Francis' United Nations address at the joint meeting of Congress in the US.